RU2827777C2 - Method, equipment and devices for encoding and decoding - Google Patents

Abstract

FIELD: data processing.

SUBSTANCE: invention relates to video encoding and decoding technologies and, in particular, to a method, equipment and devices for video encoding and decoding. Result is achieved by determining that if the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, determining the gradient value of the current pixel point based on the initial pixel value of the current pixel point and the initial pixel value of the surrounding pixel point of the current pixel point; based on the gradient value of the current pixel point and the initial pixel value of the current pixel point, and determining the refined pixel value of the current pixel point.

EFFECT: high efficiency of encoding.

15 cl, 7 dwg, 2 tbl

Description

AREA OF TECHNOLOGY

[0001] The present disclosure relates to the field of encoding and decoding technologies and, in particular, to a method, equipment and devices for encoding and decoding.

PREREQUISITES FOR THE CREATION OF THE INVENTION

[0002] In order to save space, video images are always transmitted after encoding. A complete video encoding method may include processes such as prediction, transformation, quantization, entropy encoding, filtering, etc., and predictive encoding may include intra-coding and inter-coding. Further, inter-coding refers to an operation of using video correlation in the time domain to predict pixel values of the current image using pixel values of neighboring coded images to effectively eliminate video redundancy in the time domain. Intra-coding refers to an operation of using video correlation in the spatial domain to predict the value of the current pixel using pixel values of one or more coded blocks of the current image to eliminate video redundancy in the spatial domain.

[0003] Common filtering technologies include deblocking filter (DBF) technology, sample adaptive offset (SAO) technology, and adaptive loop filter (ALF) technology. DBF technology is used to eliminate the block boundary effect caused by block coding. SAO technology is to perform classification based on sample pixel values and gradient values of surrounding blocks and add a different compensation value for each class of pixel values to ensure that the reconstructed image is closer to the original image. ALF technology is used to filter the reconstructed image using a Wiener filter to ensure that the reconstructed image is closer to the original image.

[0004] But all filtering technologies such as DBF, SAO and ALF perform classification based on the pixel value of the current pixel point or based on the relationship between the pixel value of the current pixel point and the pixel value of the surrounding pixel point, and then perform different filtering operations based on different classes. In this case, the phenomenon of overfiltering may occur: the values of the filtered pixels are much larger or much smaller than the values of the unfiltered pixels, and much larger or much smaller than the original pixel values. Thus, problems such as poor filtering effect and poor encoding performance arise.

ESSENCE OF THE INVENTION

[0005] The present disclosure provides a method and equipment for encoding and decoding, as well as corresponding devices, to improve encoding performance.

[0006] The present disclosure provides a method for encoding and decoding. The method includes:

[0007] if the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, determining a gradient value of the current pixel point based on an original pixel value of the current pixel point and an original pixel value of a surrounding pixel point of the current pixel point; based on the gradient value of the current pixel point and the original pixel value of the current pixel point, determining a refined pixel value of the current pixel point.

[0008] The present disclosure provides a decoding device. The device comprises:

[0009] a memory configured to store video data;

[00010] decoder configured:

[00011] if the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, determine a gradient value of the current pixel point based on an original pixel value of the current pixel point and an original pixel value of a surrounding pixel point of the current pixel point; based on the gradient value of the current pixel point and the original pixel value of the current pixel point, determine a refined pixel value of the current pixel point.

[00012] The present disclosure provides an encoding device. The device comprises:

[00013] memory configured to store video data;

[00014] encoder configured:

[00015] if the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, determine a gradient value of the current pixel point based on an original pixel value of the current pixel point and an original pixel value of a surrounding pixel point of the current pixel point; based on the gradient value of the current pixel point and the original pixel value of the current pixel point, determine a refined pixel value of the current pixel point.

[00016] The present disclosure provides a decoder device. The device comprises: a processor and a machine-readable storage medium that stores machine-readable instructions executable by the processor;

[00017] the processor is configured to execute machine readable instructions to perform the following steps:

[00018] if the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, determining a gradient value of the current pixel point based on an original pixel value of the current pixel point and an original pixel value of a surrounding pixel point of the current pixel point; based on the gradient value of the current pixel point and the original pixel value of the current pixel point, determining a refined pixel value of the current pixel point.

[00019] The present disclosure provides an encoder device. The device comprises a processor and a machine-readable storage medium that stores machine-readable instructions executable by the processor;

[00020] the processor is configured to execute machine readable instructions to perform the following steps:

[00021] if the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, determining a gradient value of the current pixel point based on an original pixel value of the current pixel point and an original pixel value of a surrounding pixel point of the current pixel point; based on the gradient value of the current pixel point and the original pixel value of the current pixel point, determining a refined pixel value of the current pixel point.

[00022] It can be seen from the above technical solutions that in the embodiments of the present disclosure, if the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, a refined pixel value of the current pixel point can be determined based on the gradient value of the current pixel point and the original pixel value of the current pixel point, namely, refinement is performed on the original pixel value of the current pixel point based on the gradient value of the current pixel point, in order to ensure that the refined pixel value of the current pixel point is closer to the original pixel, which improves the encoding performance. In filtering processes such as DBF, SAO and ALF, if the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, refinement can be performed on the original pixel value of the current pixel point based on the gradient value of the current pixel point, in order to improve the filtering effect and encoding performance.

BRIEF DESCRIPTION OF DRAWINGS

[00023] Fig. 1 is a schematic diagram illustrating an encoding and decoding structure according to an embodiment of the present invention.

[00024] Fig. 2A and 2B are diagrams illustrating the division of blocks according to an embodiment of the present invention.

[00025] Fig. 3 is a schematic representation,

illustrating deblocking filtering according to an embodiment of the present disclosure.

[00026] Fig. 4 is a block diagram illustrating a method for encoding and decoding according to an embodiment of the present invention.

[00027] Fig. 5A is a schematic representation,

illustrating the hardware structure of a decoder device according to an embodiment of the present disclosure.

[00028] Fig. 5B is a schematic diagram illustrating a hardware structure of an encoder device according to an embodiment of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[00029] The terms used in the embodiments of the present disclosure are intended to describe particular embodiments of the invention only and are not intended to limit the embodiments of the present disclosure. The singular forms used in the present disclosure and claims are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the phrase "and/or" as used herein refers to any one or all possible combinations of one or more related listed elements. It should be understood that while terms such as "first," "second," "third," etc. may be used in the embodiments of the present disclosure to describe various information, the information should not be limited to these terms. These terms are used only to distinguish between information of the same type. For example, within the spirit of the embodiments of the present disclosure, first information may also be referred to as second information, and similarly second information may also be referred to as first information, so the choice of terms depends on the context. Additionally, the word "if" used can be interpreted as "after", "when", or "in response to".

[00030] In order for those skilled in the art to better understand the technical solutions of the present disclosure, technical terms are briefly introduced below.

[00031] Video encoding structure: Referring to Fig. 1, a video encoding structure may be used to implement a processing flow of an encoder in the embodiments of the present disclosure. A schematic diagram of the video decoding structure may be similar to Fig. 1 and therefore will not be repeated here. The video decoding structure may be used to implement a processing flow of a decoder in the embodiments of the present disclosure. The video encoding structure and the video decoding structure may include, but are not limited to: a prediction module (e.g., an intra prediction module and an inter prediction module, etc.), a motion estimation/compensation module, a reference picture buffer, an in-loop filtering module, a reconstruction module, a transform module, a quantization module, an inverse transform module, an inverse quantization module, an entropy encoder, etc. In the encoder, the processing flow of the encoder may be provided through the interaction of these modules; in the decoder, the processing flow of the decoder may be provided through the interaction of these modules.

[00032] A loop filter is used to reduce problems such as image blocking effect or poor image quality to improve image quality. A loop filter may include: three filters, i.e. DBF, SAO and ALF. DBF is an anti-blocking filter and is used to eliminate the block boundary effect generated by block coding. SAO is an adaptive sample offset filter, which is used to perform classification based on the pixel values of samples and the gradient values of surrounding blocks and add a different compensation value for each class of pixel values to ensure that the reconstructed image is closer to the original image. ALF is an adaptive loop filter and is used to filter the reconstructed image with a Wiener filter to ensure that the reconstructed image is closer to the original image.

[00033] In some embodiments of the invention, in the video encoding process and in the video decoding process, the prediction process may include intra prediction and inter prediction. In intra prediction, due to a strong correlation in the spatial domain between neighboring blocks, the surrounding reconstructed pixels are used as reference pixels to predict the current uncoded block. Thus, it is necessary to further encode only the residual values without encoding the original values, which effectively eliminates redundancy in the spatial domain and significantly improves the compression efficiency. Inter prediction refers to the operation of using video correlation in the time domain to predict pixel values of the current image using pixel values of neighboring coded images to eliminate video redundancy in the time domain.

[00034] In some embodiments of the invention, in the video encoding process and in the video decoding process, the transform refers to transforming an image described as pixels in the spatial domain into an image of the transformed domain, which is represented as a transform coefficient. Since most images contain many flat areas and slowly changing areas, the decentralized distribution of the image energy in the spatial domain is transformed into a centralized distribution in the transformed domain in a proper transform process in order to eliminate the correlation between signals in the frequency domain and effectively compress the bit stream in conjunction with the quantization process.

[00035] In some embodiments of the invention, entropy coding refers to performing lossless coding based on the principle of information entropy, which consists in the last processing module in video compression transforming a sequence of symbols of elements representing a video sequence into a single binary bit stream for transmission or storage. The input symbols may include quantized transform coefficients, motion vector information, prediction mode information, and syntax related to transform and quantization, etc. The output of the entropy coding module is the final bit stream after compression of the original video. Entropy coding can effectively eliminate statistical redundancy of the symbols of these video elements and is one of the important tools for ensuring compression efficiency in video coding.

[00036] In some embodiments of the invention, a loop filter is used to reduce problems such as a block effect or poor image quality to improve image quality. The loop filter may include, but is not limited to: DBF, SAO and ALF, etc. For example, in a video image, the boundaries of image blocks are not continuous, and when compressing and reconstructing the image, an obvious block effect is observed, greatly affecting the image quality. The DBF technology can be used to perform deblocking filtering at the boundary. Deblocking filtering is performed at the boundaries of all Prediction Units (PU) and Transform Units (TU), wherein the deblocking filtering includes a filtering decision and a filtering operation. In the filtering decision process, a boundary strength (for example, no filtering, weak filtering or strong filtering) and a filtering parameter are obtained. In the filtering operation process, a correction for a pixel is performed based on the boundary strength and the filtering parameter. For example, when filtering is performed at the boundary, the filtering can be strong or weak filtering, which is performed using different numbers of elements.

[00037] The SAO filter is used to eliminate the ringing effect. The ringing effect refers to the pulsation phenomenon that occurs around the edge after decoding due to the quantization distortion of the high-frequency variable coefficient. The larger the size of the transformed block, the more noticeable the ringing effect is. The basic principle of SAO is to compensate the peak pixels of the reconstruction curve by adding a negative value, and the lower pixels by adding a positive value. SAO can, with the Coding Tree Unit (CTU) as the basic unit, include two main classes of compensation forms: Edge Offset (EO) and Band Offset (BO). Then, the parameter fusion technology is introduced.

[00038] The ALF filter is used to obtain an optimal filter in the mean square sense, i.e., a Wiener filter, based on the original signals and distortion signals. The ALF filter may include, but is not limited to: a 7*7 diamond filter or a 5*5 diamond filter, a 7*7 cross filter plus a 3*3 square centrosymmetric filter, or a 7*7 cross filter plus a 5*5 square centrosymmetric filter.

[00039] Intra prediction should use video correlation in the spatial domain to perform prediction on one or more coded blocks of the current block to eliminate video redundancy in the spatial domain. Intra prediction provides several prediction modes, each of which corresponds to one texture direction (except for the DC mode). For example, if the image texture is horizontal, the horizontal prediction mode can better predict the image information.

[00040] Inter prediction is to predict a pixel of the current image based on the correlation of video in the time domain using pixels of neighboring encoded images, since the video sequence contains a strong correlation in the time domain, to effectively eliminate the redundancy of the video in the time domain. All parts of inter prediction in video coding standards use block-based motion compensation technology, the basic principle of which is to find the best matching block in a previously encoded image for each block of pixels of the current image, and this process is called motion estimation (ME).

[00041] A motion vector (MV) in inter prediction can be used to represent a relative displacement between a current block of a current picture and a reference block of a reference picture. Each block obtained by division has a corresponding motion vector that needs to be transmitted to a decoder. If the motion vector of each block is coded and transmitted independently, many bits are consumed for a large number of smaller blocks. In order to reduce the number of bits used to code a motion vector, it is possible to use the correlation in the spatial domain between neighboring blocks to predict the motion vector of the current block to be coded based on the motion vector of the neighboring coded block, and then encode the prediction difference. In this way, the number of bits representing the motion vector can be effectively reduced. Based on this, in the process of encoding a motion vector of the current block, the motion vector of the neighboring coded block is first used to predict the motion vector of the current block, and then a motion vector difference (MVD) between the motion vector prediction value and the actual motion vector estimate value is coded.

[00042] For motion information, since a motion vector represents a positional deviation of the current block relative to a reference block, in order to accurately obtain information about the specified block, in addition to the motion vector, reference picture index information is also needed to indicate which reference picture is used for the current block. In a video coding technology, a reference picture list can usually be set for the current picture, and the reference picture index information indicates which reference picture specified in the reference picture list is used for the current block. In addition, many coding technologies also support multiple reference picture lists, so an index value can also be used to indicate which reference picture list is used, and this index value can be referred to as a reference direction. To summarize, in a video coding technology, motion-related information such as a motion vector, reference picture index information, and a reference direction can be collectively referred to as motion information.

[00043] There are many modes for flag encoding in video encoding. One of these modes may be adopted for a particular block. To represent which mode is adopted, each block must mark the mode by encoding the corresponding flag. For example, for the encoder, the flag value is determined by the encoder's decision, and then the flag value is encoded and passed to the decoder. For the decoder, by decoding the flag value, it is determined whether the corresponding mode is enabled.

[00044] In the process of encoding a flag, the encoding of the flag may be performed using a high-level syntax. The high-level syntax may be used to represent whether to allow the inclusion of a mode, namely, the inclusion of a mode is allowed or prohibited by the high-level syntax.

[00045] In some embodiments of the invention, the high-level syntax may be a high-level sequence parameter set syntax, or a high-level image parameter set syntax, or a high-level slice header syntax, or a high-level image header syntax, which is not limited here.

[00046] For the high-level syntax of the sequence parameter set (SPS), there is a flag for determining whether to allow some modes (tool/method) to be turned on or off in the entire video sequence (i.e., in several video images). For example, if the value of the flag is the value A (e.g., the value 1, etc.), the video sequence allows turning on the mode corresponding to the flag; or, if the value of the flag is the value B (e.g., the value 0, etc.), the video sequence prohibits turning on the mode corresponding to the flag.

[00047] For the high-level syntax of the picture parameter set (PPS), there is a flag for determining whether to allow certain modes (tool/method) to be turned on or off in an image (e.g., in a video image). If the value of the flag is equal to value A, the video image allows turning on the mode corresponding to the flag; if the value of the flag is equal to value B, the video image prohibits turning on the mode corresponding to the flag.

[00048] For the high-level syntax of the image header, there is a flag for determining whether to enable or disable some modes (tool/method) in the image header. If the value of the flag is the value A, the image header enables the mode corresponding to the flag; if the value of the flag is the value B, the image header prohibits the mode corresponding to the flag from being enabled. In some embodiments of the invention, the image header stores common information only for the current image. For example, when an image includes multiple slices, the multiple slices can share information in the image header.

[00049] For the high-level syntax of the slice header, there is a flag for determining whether to enable or disable some modes (tool/method) in the slice. If the value of the flag is the value A, the slice enables the mode corresponding to the flag; if the value of the flag is the value B, the slice prohibits the mode corresponding to the flag from being enabled. In some embodiments of the invention, one image may include one or more slices, and the high-level syntax for the slice header is a high-level syntax configured for each slice.

[00050] A high-level syntax is used to represent whether to allow the inclusion of some tools (methods), namely, the inclusion of some tools (methods) can be allowed or prohibited by a high-level syntax. In some embodiments of the invention, as described above, the high-level syntax can be a high-level syntax of a sequence parameter set, or a high-level syntax of a picture parameter set, or a high-level syntax of a slice header, or a high-level syntax of a picture header, which is not limited here, if the above-mentioned functions can be implemented.

[00051] For Rate distortion optimized (RDO), there are two metrics to evaluate the coding efficiency: the bit rate and the peak signal to noise ratio (PSNR). The smaller the bit stream, the higher the compression ratio; and the higher the PSNR, the better the quality of the reconstructed image. When selecting a mode, the discriminant formula is essentially a comprehensive evaluation of these two metrics. For example, the cost corresponding to a mode can be calculated by the following formula: J(mode)=D + λ*R, where D is the distortion, usually measured by the SSE (sum of squared error) metric, and SSE refers to the sum of the mean square differences between the reconstructed image block and the original image; λ represents the Lagrange multiplier; R represents the actual number of bits required to encode an image block in that mode, including the total number of bits required to encode mode information, motion information, residuals, etc. When selecting a mode, if the comparative decision is made for the coding mode based on the RDO principle, the optimal coding performance is usually achieved.

[00052] Block division technology: one coding tree unit (CTU) is divided into coding units (CU) by quad tree recursion. The use of intra or inter coding is determined at the CU level of the output node. The CU can be divided into two or four prediction units (PU), and the same prediction information is used in one PU. After obtaining the residual information after completing the prediction, one CU can be divided by a quad tree into a plurality of transform units (TU). For example, in the present disclosure, the current image block is one PU. In addition, the block division technology can be changed, for example, using a division structure combining a binary tree/ternary tree/quadratic tree to replace the original division mode, so as to cancel the conceptual distinction of CU, PU and TU and support more flexible division of CUs. CUs can be obtained by square or rectangular division. The CTU is first partitioned by a quad tree, and then the end node of the partition by the quad tree is partitioned by a binary tree and a ternary tree. Referring to Fig. 2A, the CUs can be partitioned by five types of partitioning, which are partitioning by a quad tree, partitioning by a horizontal binary tree, partitioning by a vertical binary tree, partitioning by a horizontal ternary tree, and partitioning by a vertical ternary tree. Referring to Fig. 2B, the partitioning of the CU in the CTU can be any combination of the above five types of partitioning. It can be known from the above that different partitioning methods allow the PUs to have different shapes, such as rectangles and squares of different sizes.

[00053] DBF filtering method (anti-block filtering): DBF filtering processing includes two processes: a filtering decision and a filtering operation.

[00054] The filtering decision includes 1) obtaining a boundary strength value (BS value); 2) deciding whether to turn on filtering; and 3) selecting a filtering strength. For the chroma component, there is only step 1), and the BS value of the luma component is directly multiplexed. For the chroma component, the filtering operation is performed only when the BS value is 2 (namely, at least one of the blocks on both sides of the current block uses the internal mode).

[00055] The filtering operation includes 1) strong filtering and weak filtering of the luminance component; and 2) filtering of the chrominance component.

[00056] In some embodiments of the invention, the processing of DBF-

Filtering usually involves performing horizontal boundary filtering (also called horizontal DBF filtering) and vertical boundary filtering (also called vertical DBF filtering) with 8×8 pixels as a block. At most three pixel points on both sides of the boundary are filtered, and at most four pixel points on both sides of the boundary are used for filtering. Therefore, horizontal DBF filtering and vertical DBF filtering of different blocks do not affect each other, namely, horizontal DBF filtering and DBF filtering can be performed in parallel.

[00057] As shown in Fig. 3, for the current block (e.g., 8*8 pixels), vertical DBF filtering is performed on three columns of pixel dots to the left of the current block and three columns of pixel dots to the right of the left block (the block to the left of the current block), and then horizontal DBF filtering is performed on three rows of pixel dots on the upper side of the current block and three rows of pixel dots on the lower side of the upper block (the block above the current block).

[00058] In some embodiments of the invention, for pixel points subject to vertical DBF filtering and horizontal DBF filtering, vertical DBF filtering is typically performed before horizontal DBF filtering. Of course, horizontal DBF filtering can also be performed before vertical DBF filtering. In subsequent embodiments of the invention, for example, vertical DBF filtering is performed before horizontal DBF filtering.

[00059] In one possible implementation, the DBF filtering flow may include the following steps.

[00060] In step S11, the boundary condition values of the horizontal direction and the vertical direction are respectively calculated with 4*4 as one.

[00061] For a CU boundary, which is an 8*8 boundary, the edge condition value is 2 (used to indicate that the luminance component and the chrominance component are both filtered). For a prediction unit (PU) boundary (for example, 1/4, 1/2, and 3/4 of the horizontal line inside 2N*hN), which is also an 8*8 boundary, the edge condition value is 1 (used to indicate that the luminance component is filtered but the chrominance component is not filtered). Under circumstances other than the above two, the edge condition value is 0.

[00062] In step S12, with the size of 4*4 as the unit (filtering is performed with the size of 8*8 as the unit, but information such as the boundary condition value is stored with the unit of 4*4), vertical filtering over all blocks is completed. When the boundary condition value is not 0, the following filtering process is performed.

[00063] 1. Filtering of brightness components (vertical filtering is performed along four rows of the vertical boundary, and horizontal filtering is performed along four columns of the horizontal boundary):

[00064] 1.1 First, it is determined whether the filtering process should be skipped. In some embodiments of the invention, if the blocks on both sides of the boundary are non-internal mode blocks with no residues and with coordinated motion, the filtering process will be skipped, and otherwise the filtering process will be performed.

[00065] 1.2 If the filtering process is not skipped, the following processing is performed.

[00066] 1.2.1 If the filtering type (dftype) of the current image is type 1 and ABS(R0 - L0)>=4*Alpha, FS is 0; otherwise, perform step 1.2.2 to determine FS. Alpha is a predetermined value, and ABS( ) indicates the operation of taking the absolute value.

[00067] 1.2.2 Calculate FL (Flatness Left, which takes values of 0, 2 or 3) and FR (Flatness Right, which takes values of 0, 2 or 3). FL and FR are used to determine the degree of flatness of the inside of both sides. Then, FS is determined based on FL and FR. For example, the following formula can be used to determine FS: FS=FL + FR.

[00068] 1.2.2.1 If ABS(L1 - L0) < Beta and ABS(L2 - L0) < Beta, FL is 3; if ABS(L1 - L0) < Beta and ABS(L2 - L0)> = Beta, FL is 2; if ABS(L1 - L0)> = Beta and ABS(L2 - L0) < Beta, FL is 1; otherwise, FL is 0. Beta is a preset value, and ABS( ) indicates the absolute value operation.

[00069] 1.2.2.2 FR can be calculated in the same way as FL and will not be repeated here.

[00070] 1.2.3 The value of BS may be determined based on FS (FS may have values of 0, 2, 3, 4, 5, or 6, and BS may have values of 0, 1, 2, 3, or 4). For example, after receiving FS, the value of BS may be determined based on the value of FS.

[00071] 1.2.3.1 If FS is less than or equal to 2 (at most one side is moderately flat), BS=0.

[00072] 1.2.3.2 If FS is 3 (only if one side is very flat), BS=(ABS(L1 - R1)<Beta) ? 1:0, namely, if ABS (L1 - R1)<Beta, BS=1, otherwise BS=0.

[00073] 1.2.3.3 If FS is 4 (both sides are moderately flat), BS=(FL=2)? 2:1, namely, if FL=2, BS=2, and if FL is not 2, BS=1.

[00074] 1.2.3.4 If FS is 5 (i.e. one side is moderately flat and the other is very flat), then:

[00075] if the filtering type (df_type) of the current image is type 1, BS=(R1=R0 && L0=L1 && ABS(R2 - L2)<Alpha) ? 3:2; namely, if the pixel value of the pixel point R1 is equal to the pixel value of the pixel point R0, and the pixel value of the pixel point L0 is equal to the pixel value of the pixel point L1, and the absolute value of the difference between the pixel value of the pixel point R2 and the pixel value of the pixel point L2 is less than Alpha (i.e., a preconfigured value), BS=3, and otherwise BS=2.

[00076] Otherwise (namely, when the filtering type (df_type) of the current image is not type 1), if the filtering type of the current image is type 0, BS=(R1=R0 && L0=L1) ? 3:2; namely, the pixel value at pixel point R1 is equal to the pixel value at pixel point R0, and the pixel value at pixel point L0 is equal to the pixel value at pixel point LI, BS=3, and otherwise BS=2.

[00077] 1.2.3.5 If FS is 6 (both sides are very flat), then:

[00078] If the filtering type (df_type) of the current image is type 1, BS=(ABS(R0 - R1)<=Beta / 4 && ABS(L0 - LI)<=Beta / 4 && ABS(R0 - L0)<Alpha) && ABS(R0 - R3)<=Beta / 2 && ABS(L0 - L3)<=Beta / 2 ? 4:3; namely, if the conditions ABS(R0 - R1)<=Beta/4, ABS(L0 - LI)<=Beta/4, ABS(R0 - L0)<Alpha, ABS(R0 - R3)<=Beta/2, and ABS(L0 - L3)<=Beta / 2 are all satisfied, BS=4, and otherwise BS=3.

[00079] Otherwise (i.e., when the filtering type (df_type) of the current image is not type 1), if the filtering type of the current image is type 0, BS=(ABS(R0 - R1)<=Beta / 4 && ABS(L0 - L1)<=Beta / 4 && ABS(R0 - L0)<Alpha) ? 4:3; namely, if the conditions ABS(R0 - R1)<=Beta / 4, ABS(L0 - LI)<=Beta / 4, and ABS(R0 - L0)<Alpha are satisfied, BS=4, and otherwise BS=3.

[00080] 1.2.4 Based on the BS value, the filtering coefficient and the number of filtered pixels are determined. For example, if four pixel points on the left or upper side of the boundary have values from L0 to L3, respectively (as shown in Fig. 3, with the left side in Fig. 3 as an example); four pixel points on the right or lower side of the boundary have values from R0 to R3, respectively (as shown in Fig. 3, with the right side in Fig. 3 as an example). For the brightness component:

[00081] 1.2.4.1 If BS=4, filtering is performed on three pixels on each of both sides of the border.

[00082] For L0 and R0, the filtering coefficient is [3, 8, 10, 8, 3]/32, namely, in order to determine the filtered pixel value of the pixel point L0, a weighted summation of the pixel values of the pixel points L2, LI, L0, R0 and R1 is performed with corresponding weighting coefficients (filtering coefficients) successively equal to 3/32, 8/32, 10/32, 8/32 and 3/32. If wj indicates the filtering coefficient, when j=-2 (the second pixel point L2 to the left of the current pixel point), wj=3/32; when j=-1 (the first pixel point L1 to the left of the current pixel point), wj=8/32; when j=0 (the current pixel point, i.e. L0), wj=10/32; When j=1 (the first pixel point R0 to the right of the current pixel point), wj=8/32; When j=2 (the second pixel point R1 to the right of the current pixel point), wj=3/32. To determine the filtered pixel value of the pixel point R0, a weighted summation is performed on the pixel values of the pixel points R2, R1, R0, L0, and L1 with respective weighting coefficients successively equal to 3/32, 8/32, 10/32, 8/32, or 3/32. If wj specifies a filtering coefficient, when j=-2 (the second pixel point R2 to the right of the current pixel point), wj=3/32; When j=-1 (the first pixel point R1 to the right of the current pixel point), wj=8/32; When j=0 (the current pixel point, i.e. R0), wj=10/32; when j=1 (the first pixel point L0 to the left of the current pixel point), wj=8/32; when j=2 (the second pixel point L1 to the left of the current pixel point), wj=3/32.

[00083] Finally, L0'=clip(L2 * 3 + LI * 8 + L0 * 10 + R0 * 8 + R1 * 3 + 16) >> 5), where L0' is the filtered pixel value of pixel point L0, L0 to L2 respectively indicate the pixel values at pixel points L0 to L2 before filtering, and R0 to R1 respectively indicate the pixel values at pixel points R0 to R1, the same notations are used below. R0 - clip((R2 *3 + R1*8 + R0*10 + L0 * 8 + L1 * 3 + 16) >> 5) >> 5).

[00084] In the above formulas, ">>" indicates a right shift operation instead of division, for example, ">>5" is equivalent to division by 2 ⁵ (32). Multiplication ("*") can be replaced by left shift, for example, a multiplied by 4 can be replaced by shifting two positions to the left, namely, a <<2; a multiplied by 10 can be replaced by ( a << 3) + ( a << 1). "<<" is a left shift operation to replace multiplication, for example, " a <<2" is equivalent to multiplication by 2 ² (4). When the division operation is performed by shifting, the result of the operation can be rounded directly, namely, when the result of the operation is a non-integer between N and N+1, the result of the operation is N. When the fractional part is greater than 0.5, the result of the operation is obtained as N+1 to improve the accuracy. Therefore, in order to increase the accuracy of the determined pixel value, 1/2 of the denominator (i.e., the dividend) may be added to the numerator of the above weighted sum during operation to achieve a rounding effect. Take L0' for example, a shift of five positions to the right is equivalent to dividing by 2 ⁵ (32). As a result, 16 may be added to the numerator of the weighted sum. clip(x) specifies a clipping operation. When x is higher than the upper limit of the specified value range, the value of x is set to the upper limit of the specified value range; when x is lower than the lower limit of the specified value range, the value of x is set to the lower limit of the specified value range.

[00085] For L1 and R1, the filter coefficient is [4, 5, 4, 3]/16, and based on this, LI'=clip((L2 * 4 + L1 * 5 + L0 * 4 + R0 * 3 + 8) >> 4), and R1'=clip((R2 * 4 + R1 *5 + R0*4 + L0*3 + 8) >> 4).

[00086] For L2 and R2, the filter coefficient is [2, 2, 2, 1, 1]/8, and thus L2'=clip((L3 * 2 + L2 * 2 + L1*2 + L0*1 + R0*1 + 4)>> 3) and R2'=clip((R3 * 2 + R2 * 2 + R1*2 + R0* 1 + L0* 1 + 4)>> 3).

[00087] 1.2.4.2 If BS=3, filtering is performed on two pixels on each of both sides of the border:

[00088] For L0 and R0, the filter coefficient is [1, 4, 6, 4, 1]/16, so L0'=clip(L2 * 1 + L1 * 4 + L0 * 6 + R0 * 4 + R1 * 1 + 8)>> 4 and R0'=clip(R2 * 1 + R1 * 4 + R0 * 6 + L0 * 4 + L1 * 1 + 8)>> 4.

[00089] For L1 and R1, the filter coefficient is [3, 8, 4, 1]/16 and thus L1'=clip((L2 * 3 + L1 * 8 + L0 * 4 + R0 * 1 + 8)>> 4) and R1'=clip((R2 * 3 + R1 * 8 + R0 * 4 + L0 * 1 + 8)>> 4).

[00090] 1.2.4.3 If BS=2, filtering is performed on one pixel on each of both sides of the border:

[00091] For L0 and R0, the filter coefficient is [3, 10, 3]/16, and based on this, L0'=clip(L1 * 3 + L0 * 10 + R0 *3 + 8)>> 4 and R0'=clip(R1 * 3 + R0 * 10 + L0 *3 + 8)>> 4.

[00092] 1.2.4.4 If BS=1, filtering is performed on one pixel on each of both sides of the boundary: for L0 and R0, the filtering coefficient is [3, 1]/4, and thus L0'=clip(L0 * 3 + R0 * 1 + 2)>>2, and R0'=clip(R0 * 3 + L0 *1 + 2)>>2.

[00093] 1.2.4.5 If BS=0, no filtering is performed, namely no filtering is performed for pixels on either side of the boundary.

[00094] 2. When the boundary condition value is 2, chroma filtering is performed at the boundary of the 16×16 block, namely, chroma component filtering is performed at the boundary of the 16×16 block. The chroma component filtering process is described below:

[00095] 2.1 First, it is determined whether filtering should be performed, and the process is similar to the process for filtering the luminance component and will not be repeated here.

[00096] 2.2 If filtering is required (i.e. the filtering process is not skipped), then FL and FR are calculated accordingly, then FS is obtained based on FL and FR, and then BS is obtained based on FS. This process is also similar to the process of filtering the luminance component, so it will not be repeated here.

[00097] 2.3 The obtained BS value (for example, 4, 3, 2, 1, 0, etc.) of the chroma component is reduced by 1, namely, the BS value may be 3, 2, 1, or 0. The filtering process of the chroma component is performed based on the BS value in the following process.

[00098] If BS=3, filtering is performed on two pixels on each of both sides of the boundary: for L0 and R0, the filtering factor is [3, 10, 3]/16, so L0'=clip(L1 * 3 + L0 * 10 + R0 *3 + 8)>> 4 and R0'=clip(R1 * 3 + R0 * 10 + L0 *3 + 8)>> 4. For L1 and R1, the filtering factor is [3, 8, 3, 2]/16, so L1'=clip((L2 * 3 + L1 * 8 + L0 * 3 + R0 * 2 + 8)>> 4) and R1'=clip((R2 * 3 + R1 * 8 + R0 * 3 + L0 * 2 + 8)>> 4).

[00099] If BS=2 or BS=1, filtering is performed on one pixel on each of both sides of the boundary: for L0 and R0, the filtering coefficient is [3, 10, 3]/16, and thus L0'=clip(L1 * 3 + L0 * 10 + R0 * 3 + 8)>> 4 and R0'=clip(R1 * 3 + R0 * 10 + L0 * 3 + 8)>> 4. If BS=0, filtering is not performed, namely, filtering is not performed for pixels on both sides of the boundary.

[000100] In some embodiments of the invention, Alpha and Beta in the above-described process are associated with the average QP value of the blocks on both sides of the boundary, namely, the average QP value of the current block and the left block of the current block (for a vertical DBF filter) or the average QP value of the current block and the top block of the current block (for a horizontal DBF filter). The values of Alpha and Beta can be obtained by looking up in a table, which is not limited here.

[000101] In step S13, with the size of 4*4 as a unit (filtering is performed with the size of 8*8 as a unit, and information such as the boundary condition value is stored with the size of 4*4 as a unit), horizontal filtering for all blocks is completed, and the implementation is similar to step S12 and is not repeated here.

[000102] In related fields, filtering technologies such as DBF, SAO and ALF perform classification based on the pixel value of the current pixel point or based on the relationship between the pixel value of the current pixel point and the pixel value of the surrounding pixel point, and then perform various filtering operations based on different classes. In this case, an overfiltering phenomenon may occur, namely, the values of the filtered pixels are much larger or much smaller than the values of the unfiltered pixels, and much larger or much smaller than the original pixel values. Thus, problems such as poor filtering effect and poor encoding performance arise.

[000103] In this regard, embodiments of the present disclosure provide a method for encoding and decoding, in which an original pixel value of a current pixel point is refined based on a gradient value of the current pixel point, in order to make the refined pixel value of the current pixel point closer to the original pixel, in order to improve encoding performance. In a filtering process, if the current pixel point in the current block satisfies a condition for turning on the extended refinement mode, the original pixel value of the current pixel point is refined based on the gradient value of the current pixel point, in order to improve the filtering effect and encoding performance.

[000104] In combination with specific embodiments, the encoding and decoding method in the embodiments of the present disclosure will be described in detail below.

[000105] Embodiment 1 of the invention: An embodiment of the present disclosure provides an encoding and decoding method that is applied in an encoder or a decoder. Fig. 4 is a block diagram illustrating the encoding and decoding method. The encoding and decoding method may include the following steps.

[000106] In step 401, if the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, the gradient value of the current pixel point is determined based on the original pixel value of the current pixel point and the original pixel value of the surrounding pixel point of the current pixel point.

[000107] In some embodiments of the invention, the gradient value of the current pixel point may be determined based on the difference between the original pixel value of the current pixel point and the original pixel value of the surrounding pixel point, namely, the gradient value of the current pixel point reflects the difference between the two pixel values.

[000108] In some embodiments of the invention, the surrounding pixel point of the current pixel point may be a neighboring pixel point for the current pixel point or a pixel point that is not a neighbor for the current pixel point. The surrounding pixel point of the current pixel point may be one or more pixel points located in the current block, or one or more pixel points located in a neighboring block of the current block. For example, the surrounding pixel point of the current pixel point may be a pixel point to the left of the current pixel point, or a pixel point to the right of the current pixel point, or a pixel point on the upper side of the current pixel point, or a pixel point on the lower side of the current pixel point. In embodiments of the invention, the position of the surrounding pixel point of the current pixel point is not limited here.

[000109] For example, as shown in Fig. 3, if the current pixel point is R0 in the current block, the surrounding pixel point of the current pixel point may be L0 in the left neighboring block of the current block. If the current pixel point is a pixel point of the first row and the second column in the current block, the surrounding pixel point of the current pixel point may be a pixel point of the eighth row and the second column in the upper neighboring block of the current block.

[000110] At step 402, a refined pixel value of the current pixel point is determined based on a gradient value of the current pixel point and an original pixel value of the current pixel point. For example, the refined pixel value of the current pixel point may be determined based on a gradient value of the current pixel point, an original pixel value of the current pixel point, a first refinement threshold value, a second refinement threshold value, a first refinement offset value, and a second refinement offset value.

[000111] In one possible implementation, if the gradient value of the current pixel point is greater than the first refinement threshold value, the refined pixel value of the current pixel point is determined based on the original pixel value of the current pixel point and the first refinement offset value. For example, the refined pixel value of the current pixel point is determined based on the sum of the original pixel value of the current pixel point and the first refinement offset value. If the gradient value of the current pixel point is less than the second refinement threshold value, the refined pixel value of the current pixel point is determined based on the original pixel value of the current pixel point and the second refinement offset value. For example, the refined pixel value of the current pixel point is determined based on the sum of the original pixel value of the current pixel point and the second refinement offset value. In some embodiments of the invention, the first refinement threshold value and the second refinement threshold value may be opposite to each other. Of course, the first refinement threshold value and the second refinement threshold value may also not be opposite numbers to each other and may be set arbitrarily.

[000112] In one possible implementation, if the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, the reference pixel point corresponding to the current pixel point may be determined from a neighboring block of the current block, and a gradient value of the reference pixel point is determined based on an original pixel value of the reference pixel point and an original pixel value of a surrounding pixel point of the reference pixel point; based on the gradient value of the reference pixel point and the original pixel value of the reference pixel point, a refined pixel value of the reference pixel point is determined.

[000113] In some embodiments of the invention, the reference point of the pixel may be a pixel point adjacent to the current pixel point in the neighboring block, or a pixel point not adjacent to the current pixel point in the neighboring block, which is not limited here. For example, as shown in Fig. 3, if the current pixel point is R0 in the current block, the reference point of the pixel may be L0 in the left neighboring block of the current block, or L1, or L2, etc. in the left neighboring block of the current block, which is not limited here. If the current pixel point is R1 in the current block, the reference point of the pixel may be L0 in the left neighboring block of the current block, or L1, or L2, etc. in the left neighboring block of the current block, which is not limited here. If the current pixel point is a pixel point of the first row and second column in the current block, the reference pixel point may be a pixel point of the eighth row and second column in the upper neighboring block of the current block, or a pixel point of the seventh row and second column in the upper neighboring block of the current block, which is not limited here.

[000114] In some embodiments of the invention, a gradient value of a pixel reference point may be determined based on a difference between an original pixel value of the pixel reference point and an original pixel value of a surrounding pixel point of the pixel reference point, namely, the gradient value reflects the difference between the two pixel values.

[000115] In some embodiments of the invention, the surrounding pixel point of the pixel reference point may be a neighboring pixel point for the pixel reference point or a pixel point that is not neighboring for the pixel reference point. The surrounding pixel point for the pixel reference point may be a pixel point located in the block where the pixel reference point is located, or a pixel point located in a neighboring block of the block where the pixel reference point is located. For example, the surrounding pixel point for the pixel reference point may be a pixel point to the left of the pixel reference point, or a pixel point to the right of the pixel reference point, or a pixel point on the upper side of the pixel reference point, or a pixel point on the lower side of the pixel reference point. In embodiments of the invention, the position of the surrounding pixel point for the pixel reference point is not limited here.

[000116] In one possible implementation, a surrounding pixel point for a reference pixel point may be a current pixel point in the current block, and similarly, a surrounding pixel point of the current pixel point may be a reference pixel point in a neighboring block of the current block.

[000117] In some embodiments of the invention, based on the gradient value of the reference point of the pixel and the original pixel value of the reference point of the pixel, determining a refined pixel value of the reference point of the pixel may include, but is not limited to: based on the gradient value of the reference point of the pixel and the original pixel value of the reference point of the pixel, a third refinement threshold value (the same as the first refinement threshold value or different from it), a fourth refinement threshold value (the same as the second refinement threshold value or different from it), a third refinement offset value (the same as the first refinement offset value or different from it), and a fourth refinement offset value (the same as the third refinement offset value or different from it), determining a refined pixel value of the reference point of the pixel.

[000118] For example, if the gradient value of the reference point of the pixel is greater than the third refinement threshold value, the refined pixel value of the reference point of the pixel is determined based on the original pixel value of the reference point of the pixel and the third refinement offset value, for example, the refined pixel value of the reference point of the pixel is determined based on the sum of the original pixel value of the reference point of the pixel and the third refinement offset value. If the gradient value of the reference point of the pixel is less than the fourth refinement threshold value, the refined pixel value of the reference point of the pixel is determined based on the original pixel value of the reference point of the pixel and the fourth refinement offset value, for example, the refined pixel value of the reference point of the pixel is determined based on the sum of the original pixel value of the reference point of the pixel and the fourth refinement offset value.

[000119] In some embodiments of the invention, the third refinement threshold value and the fourth refinement threshold value may be opposite numbers to each other. Of course, the third refinement threshold value and the fourth refinement threshold value may also not be opposite numbers to each other and may be set arbitrarily.

[000120] In one possible implementation, the first refinement threshold, the second refinement threshold, the first refinement offset value, the second refinement offset value, the third refinement threshold, the fourth refinement threshold, the third refinement offset value, and the fourth refinement offset value corresponding to the current block are determined from a high-level syntax. Optionally, the first refinement threshold, the first refinement offset value, the second refinement offset value, the third refinement threshold, the third refinement offset value, and the fourth refinement offset value corresponding to the current block are determined from a high-level syntax. Optionally, the second refinement threshold, the first refinement offset value, the second refinement offset value, the third refinement threshold, the third refinement offset value, and the fourth refinement offset value corresponding to the current block are determined from a high-level syntax. Optionally, the first refinement threshold value, the first refinement offset value, the second refinement offset value, the fourth refinement threshold value, the third refinement offset value, and the fourth refinement offset value corresponding to the current block are determined from the high-level syntax. Optionally, the second refinement threshold value, the first refinement offset value, the second refinement offset value, the fourth refinement threshold value, the third refinement offset value, and the fourth refinement offset value corresponding to the current block are determined from the high-level syntax.

[000121] In some embodiments of the invention, if the first refinement threshold value and the second refinement threshold value are opposite numbers to each other, the second refinement threshold value may be obtained after the first refinement threshold value is determined from the high-level syntax; and the first refinement threshold value may be obtained after the second refinement threshold value is determined from the high-level syntax. If the third refinement threshold value and the fourth refinement threshold value are opposite numbers to each other, the fourth refinement threshold value may be obtained after the third refinement threshold value is determined from the high-level syntax; and the third refinement threshold value may be obtained after the fourth refinement threshold value is determined from the high-level syntax.

[000122] In one possible implementation, determining that the current pixel point in the current block satisfies the condition for enabling the extended refinement mode may include, but is not limited to, the following: if the strength of the edge of the edge to be filtered corresponding to the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, determining that the current pixel point satisfies the condition for enabling the extended refinement mode. For example, if the strength of the edge of the edge to be filtered corresponding to the current pixel point is a predetermined first value, it is determined that the edge strength of the edge to be filtered satisfies the condition for enabling the extended refinement mode. In some embodiments of the invention, the predetermined first value may be equal to 0. Of course, the predetermined first value may also be another number.

[000123] Optionally, if the property information corresponding to the current block satisfies the condition for enabling the extended refinement mode, it is determined that the current pixel point in the current block satisfies the condition for enabling the extended refinement mode. In some embodiments of the invention, the property information corresponding to the current block satisfies the condition for enabling the extended refinement mode, which means that if it is determined that a filtering operation (a filtering operation for eliminating blockiness, etc.) is not allowed for the current block based on the property information corresponding to the current block, it is determined that the property information corresponding to the current block satisfies the condition for enabling the extended refinement mode.

[000124] In some embodiments of the invention, before it is determined that the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, an extended refinement mode enable flag corresponding to the current block may be obtained. If the extended refinement mode enable flag corresponding to the current block allows the current block to enable the extended refinement mode, it is determined whether the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, i.e. it is determined that the current pixel point in the current block satisfies the condition for enabling the extended refinement mode or does not satisfy the condition for enabling the extended refinement mode.

[000125] Optionally, if the extended refinement mode enable flag corresponding to the current block prohibits the current block from enabling the extended refinement mode, it is directly determined that the current pixel point in the current block does not satisfy the extended refinement mode enable condition.

[000126] In some embodiments of the invention, for a decoder, an extended refinement mode enable flag corresponding to a current block is determined from a high-level syntax, and then, based on the extended refinement mode enable flag, it is determined whether to allow the current block to enable the extended refinement mode.

[000127] For example, if the value of the extended refinement mode enable flag is the first value (e.g., 1), then the extended refinement mode enable flag allows the current block to enable the extended refinement mode; if the value of the extended refinement mode enable flag is the second value (e.g., 0), then the extended refinement mode enable flag prohibits the current block from enabling the extended refinement mode.

[000128] In one possible implementation, if the encoding and decoding method is applied to a prediction process (for example, intra prediction or inter prediction), the original pixel value of the current pixel point may be a prediction value obtained by intra prediction or inter prediction, and the refined pixel value of the current pixel point is taken as a target pixel value of the current pixel point (a final pixel value of the prediction process). If the encoding and decoding method is applied to a filtering process, the original pixel value of the current pixel point may be a prediction value before filtering, and the refined pixel value of the current pixel point is taken as a target pixel value of the current pixel point (a final pixel value of the filtering process).

[000129] It is seen from the above technical solutions that in the embodiments of the present disclosure, if the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, a refined pixel value of the current pixel point can be determined based on the gradient value of the current pixel point and the original pixel value of the current pixel point, namely, refinement is performed on the original pixel value of the current pixel point based on the gradient value of the current pixel point, in order to ensure that the refined pixel value of the current pixel point is closer to the original pixel, which improves the encoding performance. In filtering processes such as DBF, SAO and ALF, if the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, refinement can be performed on the original pixel value of the current pixel point based on the gradient value of the current pixel point, in order to improve the filtering effect and encoding performance.

[000130] In one possible implementation, if the current pixel point in the current block satisfies the condition for enabling the common filtering mode, deblocking filtering (DBF filtering) may also be performed on the original pixel value of the current pixel point to obtain a filtered pixel value of the current pixel point. Of course, deblocking filtering is only an example, and thus another filtering mode may be used to perform filtering on the original pixel value of the current pixel point. For example, SAO filtering is performed on the original pixel value of the current pixel point to obtain a filtered pixel value of the current pixel point. Alternatively, ALF filtering is performed on the original pixel value of the current pixel point to obtain a filtered pixel value of the current pixel point.

[000131] In some embodiments of the invention, with deblocking filtering as an example, with reference to steps S11-13, deblocking filtering is performed on the original pixel value of the current pixel point to obtain a filtered pixel value of the current pixel point, which is not repeated here.

[000132] From the continuous consideration of steps S11-13, it is seen that if the blocks on both sides of the boundary are non-intrinsic blocks without residues and with consistent motion, the filtering process will be skipped, and otherwise it will be performed. When the filtering process is to be performed, the BS value can also be obtained. If the BS value is 0, filtering is not performed, namely, filtering of the pixels on both sides of the boundary is not performed. If the BS value is greater than 0, filtering is performed for the pixels on both sides of the boundary. Finally, if the blocks on both sides of the boundary are non-intrinsic blocks without residues and with consistent motion, the current pixel point in the current block does not satisfy the condition for turning on the common filtering mode. If the condition that the blocks on both sides of the boundary are non-intrinsic blocks with no residues and consistent motion is not met (i.e. the blocks on both sides of the boundary are not non-intrinsic blocks, or the blocks on both sides of the boundary have residues, or the motions of the blocks on both sides of the boundary are not consistent) and BS is 0, the current pixel point in the current block does not satisfy the condition for enabling the common filtering mode. If the condition that the blocks on both sides of the boundary are non-intrinsic blocks with no residues and consistent motion is not met, and BS is greater than 0, the current pixel point in the current block satisfies the condition for enabling the common filtering mode.

[000133] It should be noted that, if the current pixel point in the current block satisfies the condition for enabling the general filtering mode, the current pixel point in the current block does not satisfy the condition for enabling the extended refinement mode; if the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, the current pixel point in the current block does not satisfy the condition for enabling the general filtering mode.

[000134] Based on the fact that the current pixel point satisfies the general filtering mode enabling condition and the deblocking filtering is performed on the original pixel value of the current pixel point to obtain the filtered pixel value of the current pixel point, it is also necessary to determine whether the current pixel point in the current block satisfies the extended filtering mode enabling condition. If the current pixel point in the current block satisfies the extended filtering mode enabling condition, the refined pixel value of the current pixel point is determined based on the filtered pixel value of the current pixel point and the original pixel value of the current pixel point, and the refined pixel value of the current pixel point is taken as the target pixel value of the current pixel point (the final pixel value of the deblocking filtering process). If the current pixel point in the current block does not satisfy the condition for enabling the advanced filtering mode, the filtered pixel value of the current pixel point is not adjusted, but is taken as the target pixel value of the current pixel point (the final pixel value of the deblocking filtering process).

[000135] In some embodiments of the invention, if the current pixel point in the current block satisfies the condition for enabling the advanced filtering mode, the refined pixel value of the current pixel point is determined based on the filtered pixel value of the current pixel point and the original pixel value of the current pixel point, which may include, but is not limited to: based on the filtered pixel value of the current pixel point, the original pixel value of the current pixel point, a first filtering threshold value, a second filtering threshold value, a first filtering offset value, and a second filtering offset value, determining the refined pixel value of the current pixel point.

[000136] In some embodiments of the invention, the first filtering threshold value and the second filtering threshold value may have opposite values. Of course, the first filtering threshold value and the second filtering threshold value may also not be opposite numbers to each other and may be set arbitrarily.

[000137] In one possible implementation, if the current pixel point in the current block satisfies the condition for turning on the common filtering mode, the pixel reference point corresponding to the current pixel point may also be determined from a neighboring block of the current block, and deblocking filtering (DBF filtering) is performed on the original pixel value of the pixel reference point to obtain a filtered pixel value of the pixel reference point. Of course, deblocking filtering is only an example, and another filtering mode may be used to perform the filtering of the original pixel value of the pixel reference point. For example, SAO filtering or ALF filtering is performed on the original pixel value of the pixel reference point to obtain a filtered pixel value of the pixel reference point.

[000138] In some embodiments of the invention, with deblocking filtering as an example, with reference to steps S11-13, deblocking filtering is performed on an original pixel value of a pixel reference point to obtain a filtered pixel value of a pixel reference point, which is not repeated here.

[000139] In some embodiments of the invention, the reference pixel point may be a pixel point adjacent to the current pixel point in the neighboring block, or a pixel point not adjacent to the current pixel point in the neighboring block, which is not limited here.

[000140] Based on the fact that the current pixel point satisfies the general filtering mode enabling condition and the deblocking filtering is performed on the original pixel value of the pixel reference point to obtain the filtered pixel value of the pixel reference point, it is also necessary to determine whether the current pixel point in the current block satisfies the extended filtering mode enabling condition. If the current pixel point in the current block satisfies the extended filtering mode enabling condition, the refined pixel value of the pixel reference point is determined based on the filtered pixel value of the pixel reference point and the original pixel value of the pixel reference point, and the refined pixel value of the pixel reference point is taken as the target pixel value of the pixel reference point (the final pixel value of the deblocking filtering process). If the current pixel point in the current block does not satisfy the condition for enabling the advanced filtering mode, the filtered pixel value of the pixel anchor point is not adjusted, and the filtered pixel value of the pixel anchor point is taken as the target pixel value of the pixel anchor point (the final pixel value of the deblocking filtering process).

[000141] In some embodiments of the invention, determining a refined pixel value of the pixel reference point based on a filtered pixel value of the pixel reference point and an original pixel value of the pixel reference point may include, but is not limited to: based on the filtered pixel value of the pixel reference point, the original pixel value of the pixel reference point, a third filtering threshold, a fourth filtering threshold, a third filtering offset value, and a fourth filtering offset value, determining a refined pixel value of the pixel reference point, where the third filtering threshold and the fourth filtering threshold may be numbers that are opposite to each other. Of course, the third filtering threshold and the fourth filtering threshold may also not be numbers that are opposite to each other and may be set arbitrarily.

[000142] In one possible implementation, the first filtering threshold value, the second filtering threshold value, the first filtering offset value, the second filtering offset value, the third filtering threshold value, the fourth filtering threshold value, the third filtering offset value, and the fourth filtering offset value corresponding to the current block are determined from a high-level syntax. Optionally, the first filtering threshold value, the first filtering offset value, the second filtering offset value, the third filtering threshold value, the third filtering offset value, and the fourth filtering offset value corresponding to the current block are determined from a high-level syntax. Optionally, the second filtering threshold value, the first filtering offset value, the second filtering offset value, the third filtering threshold value, the third filtering offset value, and the fourth filtering offset value corresponding to the current block are determined from a high-level syntax. Optionally, the second filtering threshold value, the first filtering offset value, the second filtering offset value, the fourth filtering threshold value, the third filtering offset value, and the fourth filtering offset value corresponding to the current block are determined from the high-level syntax.

[000143] In some embodiments of the invention, if the first filtering threshold value and the second filtering threshold value are opposite numbers to each other, the second filtering threshold value may be obtained after the first filtering threshold value is determined from the high-level syntax; and the first filtering threshold value may be obtained after the second filtering threshold value is determined from the high-level syntax. If the third filtering threshold value and the fourth filtering threshold value are opposite numbers to each other, the fourth filtering threshold value may be obtained after the third filtering threshold value is determined from the high-level syntax; and the third filtering threshold value may be obtained after the fourth filtering threshold value is determined from the high-level syntax.

[000144] In one possible implementation, determining that the current pixel point in the current block satisfies the condition for enabling the advanced filtering mode may include, but is not limited to, the following: if the strength of the boundary of the boundary to be filtered corresponding to the current pixel point in the current block satisfies the condition for enabling the advanced filtering mode, and the absolute value of the difference between the filtered pixel value of the current pixel point and the original pixel value of the current pixel point is greater than a predetermined threshold value (the threshold value is a positive value that is not limited herein; for example, if the first filtering threshold value and the second filtering threshold value are opposite numbers to each other, when the first filtering threshold value is a positive value, the predetermined threshold value is the same as the first filtering threshold value; when the second filtering threshold value is a positive value, the predetermined threshold value is the same as the second filtering threshold value, and of course, the predetermined threshold value may also be another value), determining that the current the pixel point satisfies the condition for enabling the advanced filtering mode. In some embodiments of the invention, the strength of the edge of the edge to be filtered corresponding to the current pixel point in the current block satisfies the condition for enabling the advanced filtering mode, which may include, but is not limited to, the following: if the strength of the edge of the edge to be filtered corresponding to the current pixel point is a predetermined second value (it is different from the predetermined first value, namely, not equal to 0, for example, the predetermined second value is greater than 0), determining that the strength of the edge of the edge to be filtered satisfies the condition for enabling the advanced filtering mode.

[000145] In some embodiments of the invention, before it is determined that the current pixel point in the current block satisfies the condition for enabling the extended filtering mode, an enabling flag of the extended filtering mode corresponding to the current block may be obtained. If the enabling flag of the extended filtering mode corresponding to the current block allows the current block to enable the extended filtering mode, it is determined whether the current pixel point in the current block satisfies the condition for enabling the extended filtering mode, i.e. it is determined that the current pixel point in the current block satisfies the condition for enabling the extended filtering mode or does not satisfy the condition for enabling the extended filtering mode.

[000146] Optionally, if the advanced filtering mode enable flag corresponding to the current block prohibits the current block from enabling the advanced filtering mode, it is directly determined that the current pixel point in the current block does not satisfy the condition for enabling the advanced filtering mode.

[000147] In some embodiments of the invention, for the decoder, the extended filtering mode enable flag corresponding to the current block is analyzed from the high-level syntax, and then, based on the extended filtering mode enable flag, it is determined whether to allow the current block to enable the extended filtering mode.

[000148] For example, if the value of the extended filter mode enable flag is the first value (e.g., 1), the extended filter mode enable flag allows the current block to enable the extended filter mode; if the value of the extended filter mode enable flag is the second value (e.g., 0), the extended filter mode enable flag prohibits the current block from enabling the extended filter mode.

[000149] In some embodiments of the invention, in the above embodiments of the invention, the high-level syntax includes, but is not limited to, one of the following syntaxes: high-level sequence parameter set (SPS) syntax, high-level picture parameter set (PPS) syntax, high-level picture header syntax, high-level image syntax, high-level slice header syntax, high-level coding tree unit (CTU) syntax, and high-level coding unit (CU) syntax.

[000150] In some embodiments of the invention, in the above embodiments of the invention, the pixel value of the current pixel point in the current block may be a luminance component or a chrominance component.

[000151] It is seen from the above technical solutions that, if the current pixel point in the current block satisfies the condition for enabling the advanced filtering mode, the refined pixel value of the current pixel point can be determined based on the filtered pixel value of the current pixel point and the original pixel value of the current pixel point, namely, the refinement is performed on the original pixel value of the current pixel point based on the filtered pixel value of the current pixel point, in order to ensure that the refined pixel value of the current pixel point is closer to the original pixel, which improves the encoding performance. In filtering processes such as DBF, SAO and ALF, if the current pixel point in the current block satisfies the condition for enabling the advanced filtering mode, the refinement of the original pixel value of the current pixel point can be performed based on the filtered pixel value of the current pixel point, in order to improve the filtering effect and encoding performance.

[000152] Embodiment 2 of the invention: when filtering is to be performed, it is first determined whether to skip the filtering process. For example, if the blocks on both sides of the boundary (i.e., the current block and the neighboring block of the current block, which is the left neighboring block of the current block for the vertical boundary, and is the upper neighboring block of the current block for the horizontal boundary) are non-intra-mode blocks (namely, neither the current block nor the neighboring block is an intra-mode block), without residues (no residues between the current block and the neighboring block), but with matched motion (the current block and the neighboring block are matched in motion), the filtering process is skipped, otherwise the filtering process is not skipped. Thus, "skip the filtering process" can be used as a condition for turning on the extended refinement mode, namely, if the filtering process is skipped for the current pixel point in the current block, the current pixel point in the current block satisfies the condition for turning on the extended refinement mode. When the current pixel point satisfies the condition for enabling the advanced refinement mode, the original pixel value of the current pixel point can be refined based on the advanced refinement mode to make the pixel value closer to the original pixel.

[000153] In some embodiments of the invention, if the property information corresponding to the current block satisfies the condition for enabling the extended refinement mode, it is determined that the current pixel point in the current block satisfies the condition for enabling the extended refinement mode. The property information corresponding to the current block is used to indicate whether the blocks on both sides of the boundary are non-intra-mode blocks, to indicate whether the blocks on both sides of the boundary do not have residues, and to indicate whether the blocks on both sides of the boundary are motion-consistent. As a result, if the property information corresponding to the current block is used to indicate that the blocks on both sides of the boundary are blocks that do not belong to the internal mode, to indicate that the blocks on both sides of the boundary have no residues, and to indicate whether the blocks on both sides of the boundary are motion-matched, this indicates that the property information corresponding to the current block satisfies the condition for enabling the extended refinement mode, and it is determined that the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, namely, each pixel point in the current block satisfies the condition for enabling the extended refinement mode. Optionally, if the property information corresponding to the current block is used to indicate that all blocks on both sides of the boundary are not blocks that do not belong to the internal mode, and/or the property information corresponding to the current block is used to indicate that blocks on both sides of the boundary have residues, and/or the property information corresponding to the current block is used to indicate that blocks on both sides of the boundary are not matched in motion, this indicates that the property information corresponding to the current block does not satisfy the condition for enabling the extended refinement mode, and it is determined that the current pixel point in the current block does not satisfy the condition for enabling the extended refinement mode, namely, each pixel point in the current block does not satisfy the condition for enabling the extended refinement mode.

[000154] In some embodiments of the invention, when the current pixel point satisfies the condition for turning on the extended refinement mode, the original pixel value of the current pixel point may be refined based on the extended refinement mode. For example, the gradient value of the current pixel point is determined based on the original pixel value of the current pixel point, and the refined pixel value of the current pixel point is determined based on the gradient value of the current pixel point and the original pixel value of the current pixel point. The process of refining the refined pixel value may relate to subsequent embodiments of the invention and will not be repeated here.

[000155] Embodiment 3 of the invention: when filtering is to be performed, it is first determined whether to skip the filtering process. For example, if the blocks on both sides of the boundary are non-intra mode blocks without residues but with matched motion, the filtering process is skipped, otherwise the filtering process is not skipped. When the filtering process is not skipped, the BS value may also be determined. If the BS value is greater than 0 (for example, the BS value is 1, 2, 3, 4, etc.), filtering may be performed for the pixels on both sides of the boundary. If the BS value is 0, filtering is not performed, namely, filtering is not performed for the pixels on both sides of the boundary. Thus, "the BS value is 0" can be taken as a condition for turning on the extended refinement mode, namely: if the BS value of the current pixel point in the current block is 0, the current pixel point in the current block satisfies the condition for turning on the extended refinement mode; If the BS value of the current pixel point in the current block is greater than 0, the current pixel point in the current block does not satisfy the condition for enabling the advanced refinement mode.

[000156] In some embodiments of the invention, if the edge strength of the edge to be filtered corresponding to the current pixel point in the current block satisfies the condition for enabling the advanced refinement mode, it is determined that the current pixel point satisfies the condition for enabling the advanced refinement mode. For example, the edge strength of the edge to be filtered corresponding to the current pixel point is first determined. If the edge strength is a predetermined first value, it is determined that the edge strength satisfies the condition for enabling the advanced refinement mode. The predetermined first value can be set based on experience, for example, set to 0. Finally, the edge strength of the edge to be filtered corresponding to the current pixel point is 0, which indicates that the edge strength of the edge to be filtered corresponding to the current pixel point satisfies the condition for enabling the advanced refinement mode, and it is determined that the current pixel point satisfies the condition for enabling the advanced refinement mode.

[000157] Optionally, if the strength of the boundary of the boundary to be filtered corresponding to the current pixel point in the current block does not satisfy the condition for enabling the extended refinement mode, it is determined that the current pixel point does not satisfy the condition for enabling the extended refinement mode. For example, if the strength of the boundary of the boundary to be filtered corresponding to the current pixel point is not a predetermined first value, it is determined that the strength of the boundary does not satisfy the condition for enabling the extended refinement mode. Thus, it is determined that the current pixel point in the current block does not satisfy the condition for enabling the extended refinement mode.

[000158] In some embodiments of the invention, when the current pixel point satisfies the condition for turning on the extended refinement mode, the original pixel value of the current pixel point may be refined based on the extended refinement mode to make the pixel value closer to the original pixel. For example, the gradient value of the current pixel point is determined based on the original pixel value of the current pixel point, and the refined pixel value of the current pixel point is determined based on the gradient value of the current pixel point and the original pixel value of the current pixel point. The process of refining the refined pixel value may relate to subsequent embodiments of the invention.

[000159] Embodiment 4 of the invention: when filtering is to be performed, it is first determined whether to skip the filtering process. For example, if the blocks on both sides of the boundary are non-internal mode blocks without residues but with coordinated motion, the filtering process is skipped, otherwise, the filtering process is not skipped. When the filtering process is not skipped, the BS value can also be determined. If the BS value is greater than 0 (for example, the BS value is 1, 2, 3, 4, etc.), filtering can be performed for the pixels on both sides of the boundary. If the BS value is 0, filtering is not performed, namely, filtering is not performed for the pixels on both sides of the boundary. Thus, "the BS value is greater than 0" can be taken as a condition for turning on the common filtering mode, namely: if the BS value of the current pixel point in the current block is greater than 0, the current pixel point in the current block satisfies the condition for turning on the common filtering mode; if the BS value of the current pixel point in the current block is 0, the current pixel point in the current block does not satisfy the condition for enabling the general filtering mode.

[000160] In some embodiments of the invention, if the strength of the boundary of the boundary to be filtered corresponding to the current pixel point in the current block satisfies the condition for turning on the general filtering mode, it is determined that the current pixel point satisfies the condition for turning on the general filtering mode. For example, the strength of the boundary of the boundary to be filtered corresponding to the current pixel point may be determined first. If the strength of the boundary is a predetermined second value, it is determined that the strength of the boundary satisfies the condition for turning on the general filtering mode. The predetermined second value may be set based on experience, for example, it may be set greater than 0, for example, equal to 1, 2, 3, 4, etc. In short, if the boundary strength of the boundary to be filtered corresponding to the current pixel point is greater than 0 (i.e., the boundary strength is not 0), it indicates that the boundary strength of the boundary to be filtered corresponding to the current pixel point satisfies the condition for enabling the general filtering mode, and it is determined that the current pixel point satisfies the condition for enabling the general filtering mode.

[000161] Alternatively, if the edge strength of the edge to be filtered corresponding to the current pixel point in the current block does not satisfy the condition for enabling the general filtering mode, it is determined that the current pixel point does not satisfy the condition for enabling the general filtering mode. For example, the edge strength (for example, 0) of the edge to be filtered corresponding to the current pixel point is not a predetermined second value, it is determined that the edge strength does not satisfy the condition for enabling the general filtering mode. Thus, it is determined that the current pixel point in the current block does not satisfy the condition for enabling the general filtering mode.

[000162] In some embodiments of the invention, when the current pixel point satisfies the condition for enabling the common filtering mode, deblocking filtering (DBF filtering, which is used here as an example) may be performed on the original pixel value of the current pixel point to obtain a filtered pixel value of the current pixel point.

[000163] Embodiment 5 of the invention: based on the fact that the current pixel point in the current block satisfies the condition for enabling the general filtering mode, and deblocking filtering is performed on the original pixel value of the current pixel point to obtain a filtered pixel value of the current pixel point, it should also be determined whether the current pixel point in the current block satisfies the condition for enabling the advanced filtering mode. For example, it is determined whether the absolute value of the difference between the filtered pixel value of the current pixel point and the original pixel value of the current pixel point exceeds a predetermined threshold value. If the absolute value is greater than the predetermined threshold value, it is determined that the current pixel point in the current block satisfies the condition for enabling the advanced filtering mode; if the absolute value is not greater than the predetermined threshold value, it is determined that the current pixel point in the current block does not satisfy the condition for enabling the advanced filtering mode. Finally, satisfying the condition for enabling the advanced filtering mode by the current pixel point in the current block may include the following: if the strength of the boundary of the boundary to be filtered corresponding to the current pixel point in the current block satisfies the condition for enabling the advanced filtering mode, and the absolute value of the difference between the filtered pixel value of the current pixel point and the original pixel value of the current pixel point exceeds a predetermined threshold value, determining that the current pixel point satisfies the condition for enabling the advanced filtering mode.

[000164] In combination with specific embodiments of the invention, the condition for enabling the extended filtering mode will be described below.

[000165] When filtering is to be performed, it is first determined whether to skip the filtering process. When the filtering process is not skipped, the BS value may also be determined. If the BS value is greater than 0, filtering may be performed for the pixels on both sides of the boundary. Therefore, "the BS value is greater than 0" is taken as a condition for turning on the advanced filtering mode, namely, "the BS value is greater than 0" is taken as a condition for turning on the common filtering mode and the advanced filtering mode simultaneously. When the BS value is greater than 0, deblocking filtering must be performed on the original pixel value of the current pixel point to obtain the filtered pixel value of the current pixel point. After obtaining the filtered pixel value of the current pixel point, it is also determined whether the absolute value of the difference between the filtered pixel value of the current pixel point and the original pixel value of the current pixel point exceeds a predetermined threshold value, and “the absolute value of the difference is greater than the predetermined threshold value” is taken as a condition for turning on the advanced filtering mode.

[000166] Finally, if the edge strength of the edge to be filtered corresponding to the current pixel point in the current block satisfies the condition for enabling the advanced filtering mode, and the absolute value of the difference between the filtered pixel value of the current pixel point and the original pixel value of the current pixel point exceeds a predetermined threshold value, it is determined that the current pixel point satisfies the condition for enabling the advanced filtering mode. Otherwise, it is determined that the current pixel point does not satisfy the condition for enabling the advanced filtering mode. For example, the edge strength of the edge to be filtered corresponding to the current pixel point is first determined. If the edge strength is a predetermined second value, it is determined that the edge strength satisfies the condition for enabling the advanced filtering mode. The predetermined second value is set based on experience, for example, it is set to be greater than 0, for example, equal to 1, 2, 3, or 4, etc.

[000167] In some embodiments of the invention, when the current pixel point satisfies the condition for enabling the extended filtering mode, the refined pixel value of the current pixel point may be determined based on the filtered pixel value of the current pixel point and the original pixel value of the current pixel point, and then the refined pixel value of the current pixel point is taken as the target pixel value of the current pixel point (the final pixel value of the deblocking filtering process). If the current pixel point in the current block does not satisfy the condition for enabling the extended filtering mode, the filtered pixel value of the current pixel point is not adjusted, but is taken as the target pixel value of the current pixel point (the final pixel value of the deblocking filtering process).

[000168] It can be seen from the above embodiments 1, 2, 3, 4 and 5 that, based on the advanced refinement mode, the common filtering mode and the advanced filtering mode used in the present disclosure, the original pixel value of the current pixel point is processed to obtain a target pixel value of the current pixel point (i.e., a final pixel value). For example, if the current pixel point satisfies the condition for turning on the advanced refinement mode, the original pixel value of the current pixel point can be refined based on the gradient value of the current pixel point in the advanced refinement mode to obtain a refined pixel value of the current pixel point, and the refined pixel value is taken as the target pixel value. Another example: if the current pixel point satisfies the enabling condition of the common filtering mode but does not satisfy the enabling condition of the advanced filtering mode, the original pixel value of the current pixel point may be filtered in the common filtering mode to obtain a filtered pixel value of the current pixel point, and the filtered pixel value is taken as a target pixel value. In another example, if the current pixel point satisfies both the enabling condition of the common filtering mode and the enabling condition of the advanced filtering mode, the original pixel value of the current pixel point is filtered in the advanced filtering mode to obtain a filtered pixel value of the current pixel point, and the original pixel value of the current pixel point is refined based on the filtered pixel value of the current pixel point to obtain a refined pixel value of the current pixel point, and then the filtered pixel value is taken as a target pixel value.

[000169] In one possible implementation, deblocking filtering is performed for the current block, the original pixel value of the current pixel point in the current block can be processed based on the advanced refinement mode, the common filtering mode, or the advanced filtering mode, namely, the advanced refinement mode, the common filtering mode, and the advanced filtering mode belong to the deblocking filtering mode, that is, the advanced refinement mode, the common filtering mode, and the advanced filtering mode can be submodes in the deblocking filtering mode. Based on this, in the deblocking filtering mode, it can be determined whether to use the advanced refinement mode, or the common filtering mode, or the advanced filtering mode to process the original pixel value of the current pixel point.

[000170] Of course, the advanced refinement mode, the common filtering mode, and the advanced filtering mode may also refer to another type of filtering mode, such as the SAO filtering mode or the ALF filtering mode, namely, the advanced refinement mode, the common filtering mode, and the advanced filtering mode may be sub-modes in the SAO filtering mode or sub-modes in the ALF filtering mode. Therefore, in the SAO filtering mode or the ALF filtering mode, it may be determined to use the advanced refinement mode, or the common filtering mode, or the advanced filtering mode to process the original pixel value of the current pixel point.

[000171] In some embodiments of the invention, for example, the advanced refinement mode, the common filtering mode, and the advanced filtering mode relate to the deblocking filtering mode. Thus, the common filtering mode may be called the common mode of the deblocking filtering mode, namely, after the deblocking filtering is performed on the original pixel value of the current pixel point to obtain the filtered pixel value, the pixel value is no longer adjusted. The advanced filtering mode may be called the deblocking refinement (DBR) mode, namely, after the deblocking filtering is performed on the original pixel value of the current pixel point to obtain the filtered pixel value, the refinement of the pixel value filtered by the deblocking filtering must also be performed. The advanced refinement mode may be referred to as an alternative deblocking refinement (ADBR) mode, namely, without performing deblocking filtering on the original pixel value of the current pixel point, the original pixel value of the current pixel point is refined directly.

[000172] Embodiment 6 of the invention: for embodiments 1, 2 and 3 of the invention, the original pixel value of the current pixel point may be refined based on the extended refinement mode. Refining the original pixel value may include the following steps.

[000173] In step S21, based on the original pixel value of the current pixel point and the original pixel value of the surrounding pixel point of the current pixel point, a gradient value of the current pixel point is determined. For example, the gradient value of the current pixel point is determined based on the difference between the original pixel value of the current pixel point and the original pixel value of the surrounding pixel point, which is not limited here.

[000174] In step S22, a reference point of a pixel corresponding to the current pixel point is determined from a neighboring block of the current block (for a vertical boundary, the neighboring block is the left neighboring block of the current block, and for a horizontal boundary, the neighboring block is the upper neighboring block of the current block), and a gradient value of the reference point of a pixel is determined based on an original pixel value of the reference point of a pixel and an original pixel value of a surrounding pixel point of the reference point of a pixel. For example, the gradient value of the reference point of a pixel may be determined based on a difference between an original pixel value of the reference point of a pixel and an original pixel value of a surrounding pixel point of the reference point of a pixel, which is not limited herein.

[000175] In some embodiments of the invention, the gradient value of the current pixel point is determined based on the original pixel value of the current pixel point and the original pixel value of the surrounding pixel point of the current pixel point (e.g., the surrounding pixel point is the reference pixel point), and the gradient value of the reference pixel point is determined based on the original pixel value of the surrounding pixel point of the reference pixel point (e.g., the surrounding pixel point is the current pixel point) and the original pixel value of the reference pixel point.

[000176] For example, it is assumed that pi indicates the original pixel value of the current pixel point in the current block, that is, the original pixel value of the surrounding pixel point of the pixel reference point, and qi indicates the original pixel value of the pixel reference point in the neighboring block, namely, the original pixel value of the surrounding pixel point of the current pixel point, and in other words, pi and qi respectively indicate the original pixel values on both sides of the boundary. The gradient value DPi of the current pixel point pi can be determined as follows: DPi=(pi - qi + 2) >> 2. The gradient value DQi of the pixel reference point qi can be determined as follows: DQi=(qi - pi + 2) >> 2. Of course, the above is only an example of determining the gradient value of the current pixel point and the gradient value of the pixel reference point, and no limitations are made here. Obviously, the gradient value of the current pixel point is determined based on the difference between the original pixel value of the current pixel point and the original pixel value of the pixel reference point, and the gradient value of the pixel reference point is determined based on the difference between the original pixel value of the pixel reference point and the original pixel value of the current pixel point.

[000177] For example, when the current pixel point pi is p0 (corresponds to R0 in Fig. 3) and the reference pixel point qi is q0 (corresponds to L0 in Fig. 3), the gradient value DP0 of the current pixel point p0 is determined as follows: DP0=(p0-q0 + 2) >> 2; the gradient value DQ0 of the reference pixel point q0 is determined as follows: DQ0=(q0-p0 + 2) >> 2. DP0=(p0-q0 + 2) >> 2 can also be expressed as DP0=(p0-q0 + 1) >> 1, and DQ0=(q0-p0 + 2) >> 2 can also be expressed as DQ0=(q0-p0 + 1) >> 1.

[000178] In step S23, a refined pixel value of the current pixel point is determined based on a gradient value of the current pixel point and an original pixel value of the current pixel point. For example, if the gradient value of the current pixel point is greater than a first refinement threshold value, the refined pixel value of the current pixel point is determined based on the original pixel value of the current pixel point and a first refinement offset value (also referred to as a first refinement offset value). If the gradient value of the current pixel point is less than a second refinement threshold value, the refined pixel value of the current pixel point is determined based on the original pixel value of the current pixel point and the second refinement offset value. In some embodiments of the invention, the first refinement threshold value and the second refinement threshold value may be opposite to each other.

[000179] In step S24, a refined pixel value of the reference point of the pixel is determined based on the gradient value of the reference point of the pixel and the original pixel value of the reference point of the pixel. For example, if the gradient value of the reference point of the pixel is greater than a third refinement threshold value, the refined pixel value of the reference point of the pixel is determined based on the original pixel value of the reference point of the pixel and a third refinement offset value (also called a third refinement offset value). If the gradient value of the reference point of the pixel is less than a fourth refinement threshold value, the refined pixel value of the reference point of the pixel is determined based on the original pixel value of the reference point of the pixel and a fourth refinement offset value. In the example, the third refinement threshold value and the fourth refinement threshold value may be opposite numbers to each other.

[000180] For example, if the gradient value DPi of the current pixel point pi is greater than alt_dbr_th (alt_dbr_th represents the first refinement threshold value), the refined pixel value Pi of the current pixel point pi may be determined as follows: Pi=clip(pi + alt_dbr_offset0), where alt_dbr_offset0 represents the first refinement offset value. Alternatively, if the gradient value DPi of the current pixel point pi is less than -alt_dbr_th (-alt_dbr_th represents the second refinement threshold value), the refined pixel value Pi of the current pixel point pi may be determined as follows: Pi=clip(pi + alt_dbr_offset1), where alt_dbr_offset1 represents the second refinement offset value.

[000181] In the above embodiment of the invention, i may be 0, 1, or 2. For example, i is 0, in which case, if DP0>dbr_th, then P0=clip(p0 + alt_dbr_offset0); if DP0<-dbr_th, then P0=clip(p0 + alt_dbr_offset1).

[000182] For example, if the gradient value DQi of the anchor point of the pixel qi is greater than alt dbr_th (alt dbr_th is the third refinement threshold value, and the third refinement threshold value is the same as the first refinement threshold value. In practical applications, the third refinement threshold value may be different from the first refinement threshold value), the refined pixel value Qi of the anchor point of the pixel qi can be determined as follows: Qi=clip(qi + alt_dbr_offset0), where alt_dbr_offset0 represents the third refinement offset value. Here, the third refinement offset value is the same as the first refinement offset value. In practical applications, the third refinement offset value may also be different from the first refinement offset value.

[000183] Alternatively, if the gradient value DQi of the reference point of the pixel qi is less than alt dbr_th (alt dbr_th is the fourth refinement threshold value, and the fourth refinement threshold value is the same as the second refinement threshold value. In practical applications, the fourth refinement threshold value may be different from the second refinement threshold value), the refined pixel value Qi of the reference point of the pixel qi may be determined as follows: Qi=clip(qi + alt_dbr_offset1), where alt_dbr_offset1 represents the fourth refinement offset value. Here, the fourth refinement offset value is the same as the second refinement offset value. In practical applications, the fourth refinement offset value may also be different from the second refinement offset value.

[000184] In the above embodiment of the invention, i may be 0, 1, or 2. For example, when i is 0, if DQ0>dbr_th, then Q0=clip(q0 + alt_dbr_offset0); if DQ0<-dbr_th, then Q0=clip(q0 + alt_dbr_offset1).

[000185] In the above embodiment of the invention, pi represents the original pixel point of the current pixel point, DPi represents the gradient value of the current pixel point, Pi represents the refined pixel value of the current pixel point, qi represents the original pixel value of the reference pixel point, DQi represents the gradient value of the reference pixel point, Qi represents the refined pixel value of the reference pixel point, clip(x) means that x is limited to [0, 2^(bit_depth)-1] (including 0 and 2^(bit_depth)-1), and bit_depth represents the bit depth of the image and is typically 8, 10, or 12, etc.

[000186] In one possible implementation, for a decoder, a first refinement threshold value, a first refinement offset value, a second refinement offset value, a third refinement threshold value, a third refinement offset value, and a fourth refinement offset value corresponding to the current block may be parsed from a high-level syntax. Since the first refinement threshold value and the second refinement threshold value are opposite numbers to each other, and the third refinement threshold value and the fourth refinement threshold value are opposite numbers to each other, the decoder may determine the second refinement threshold value and the fourth refinement threshold value.

[000187] In another possible implementation, for a decoder, a first refinement threshold value, a first refinement offset value, a second refinement offset value, a fourth refinement threshold value, a third refinement offset value, and a fourth refinement offset value corresponding to the current block can be parsed from a high-level syntax. Since the first refinement threshold value and the second refinement threshold value are opposite numbers to each other, and the third refinement threshold value and the fourth refinement threshold value are opposite numbers to each other, the decoder can determine the second refinement threshold value and the third refinement threshold value.

[000188] In another possible implementation, for a decoder, a second refinement threshold value, a first refinement offset value, a second refinement offset value, a third refinement threshold value, a third refinement offset value, and a fourth refinement offset value corresponding to the current block can be parsed from a high-level syntax. Since the first refinement threshold value and the second refinement threshold value are opposite numbers to each other, and the third refinement threshold value and the fourth refinement threshold value are opposite numbers to each other, the decoder can determine the first refinement threshold value and the fourth refinement threshold value.

[000189] In another possible implementation, for a decoder, a second refinement threshold value, a first refinement offset value, a second refinement offset value, a fourth refinement threshold value, a third refinement offset value, and a fourth refinement offset value corresponding to the current block can be parsed from a high-level syntax. Since the first refinement threshold value and the second refinement threshold value are opposite numbers to each other, and the third refinement threshold value and the fourth refinement threshold value are opposite numbers to each other, the decoder can determine the first refinement threshold value and the third refinement threshold value.

[000190] In another possible implementation for the decoder, the first refinement threshold value (or the second refinement threshold value, or the third refinement threshold value, or the fourth refinement threshold value, namely, the other three refinement threshold values can be obtained from one refinement threshold value), the first refinement offset value (or the third refinement offset value), the second refinement offset value (or the fourth refinement offset value) corresponding to the current block can be analyzed from a high-level syntax. Therefore, since the first refinement threshold value and the second refinement threshold value are opposite numbers to each other, the second refinement threshold value can be determined. Since the first refinement threshold value and the third refinement threshold value are the same, the third refinement threshold value can be determined. Since the third refinement offset value and the first refinement offset value are the same, the third refinement offset value can be determined. Since the fourth refinement offset value and the second refinement offset value are the same, the fourth refinement offset value can be determined. Since the third refinement threshold and the fourth refinement threshold are opposite numbers to each other, the fourth refinement threshold can be determined.

[000191] Of course, the above are only a few examples, which are not limited here, provided that the decoder can obtain a first refinement threshold value, a second refinement threshold value, a third refinement threshold value, a fourth refinement threshold value, a first refinement offset value, a second refinement offset value, a third refinement offset value, and a fourth refinement offset value. The above-mentioned values can be obtained by analysis or inference.

[000192] In the above embodiment of the invention, the high-level syntax includes, but is not limited to, one of the following syntaxes: SPS high-level syntax, PPS high-level syntax, image header high-level syntax, image high-level syntax; slice header high-level syntax, CTU high-level syntax, and CU high-level syntax. Of course, the above are only a few examples of high-level syntaxes, and the types of high-level syntaxes are not limited here, as long as the refinement threshold values and the refinement offset values corresponding to the current block can be carried by the high-level syntaxes.

[000193] In the above-described embodiments of the invention, the pixel value of the current pixel point in the current block may be a luminance component or a chrominance component.

[000194] In one possible implementation, the extended refinement mode enable flag indicates whether to enable the extended refinement mode. If the extended refinement mode enable flag allows the current block to enable the extended refinement mode, it is required to determine whether the current pixel point in the current block satisfies the condition for enabling the extended refinement mode. If the current pixel point satisfies the condition for enabling the extended refinement mode, the original pixel value of the current pixel point is refined based on the extended refinement mode. If the extended refinement mode enable flag prohibits the current block from enabling the extended refinement mode, it is directly determined that each pixel point in the current block does not satisfy the condition for enabling the extended refinement mode, and the original pixel value of the current pixel point is not adjusted based on the extended refinement mode. Therefore, if the extended refinement mode enable flag corresponding to the current block allows the current block to enable the extended refinement mode, it is determined whether the current pixel point in the current block satisfies the extended refinement mode enable condition. If the extended refinement mode enable flag corresponding to the current block prohibits the current block from enabling the extended refinement mode, it is determined that each pixel point in the current block does not satisfy the extended refinement mode enable condition.

[000195] In some embodiments of the invention, for a decoder, the extended refinement mode enable flag corresponding to the current block may be parsed from a high-level syntax. For example, if the extended refinement mode enable flag has a first value (e.g., 1), this indicates that the extended refinement mode enable flag allows the current block to enable the extended refinement mode; if the extended refinement mode enable flag has a second value (e.g., 0), this indicates that the extended refinement mode enable flag prohibits the current block from enabling the extended refinement mode.

[000196] In the above embodiment of the invention, the high-level syntax includes, but is not limited to, one of the following syntaxes: SPS high-level syntax, PPS high-level syntax, image header high-level syntax, image high-level syntax; slice header high-level syntax, CTU high-level syntax, and CU high-level syntax. Of course, the above are only a few examples of high-level syntaxes, and the types of high-level syntaxes are not limited here, as long as the extended refinement mode enable flag corresponding to the current block can be carried by the high-level syntaxes.

[000197] Embodiment 7 of the invention: for embodiments 1 and 5 of the invention, the original pixel value of the current pixel point may be refined based on the advanced filtering mode. Refining the original pixel value of the current pixel point may include the following steps.

[000198] In step S31, filtering is performed to eliminate blockiness of the original pixel value of the current pixel point to obtain a filtered pixel value of the current pixel point.

[000199] In step S32, a reference point of a pixel corresponding to the current pixel point is determined from a neighboring block of the current block (for a vertical boundary, the neighboring block is the left neighboring block of the current block, and for a horizontal boundary, the neighboring block is the upper neighboring block of the current block), and deblocking filtering is performed on the original pixel value of the reference point of the pixel to obtain a filtered pixel value of the reference point of the pixel.

[000200] In some embodiments of the invention, deblocking filtering is performed on the original pixel value of the current pixel point based on deblocking filtering (DBF) to obtain a filtered pixel value of the current pixel point, and deblocking filtering is performed on the original pixel value of the reference pixel point based on the DBF to obtain a filtered pixel value of the reference pixel point. Of course, filtering can also be performed on the original pixel value of the current pixel point based on SAO to obtain a filtered pixel value of the current pixel point, and filtering is performed on the original pixel value of the reference pixel point based on SAO to obtain a filtered pixel value of the reference pixel point. Alternatively, filtering may be performed on the original pixel value of the current pixel point based on the ALF to obtain a filtered pixel value of the current pixel point, and filtering is performed on the original pixel value of the reference pixel point based on the ALF to obtain a filtered pixel value of the reference pixel point. For ease of description, in the following embodiments of the invention, for example, filtering for deblocking is performed on the original pixel value of the current pixel point and the reference pixel point based on the DBF.

[000201] Referring to Fig. 3, depending on the position of the current pixel point, only horizontal DBF filtering may be performed for the current pixel point and the reference pixel point, or only vertical DBF filtering may be performed for the current pixel point and the reference pixel point, or vertical DBF filtering may be performed first at the current pixel point and the reference pixel point, and then horizontal DBF filtering may be performed at the current pixel point and the reference pixel point.

[000202] In step S33, based on the filtered pixel value of the current pixel point and the original pixel value of the current pixel point, a refined pixel value of the current pixel point is determined. For example, based on the filtered pixel value of the current pixel point, the original pixel value of the current pixel point, the first filtering threshold value, the second filtering threshold value, the first filtering offset value, and the second filtering offset value, a refined pixel value of the current pixel point is determined. The first filtering threshold value and the second filtering threshold value may be numbers that are opposite to each other.

[000203] In step S34, based on the filtered pixel value of the reference point of the pixel and the original pixel value of the reference point of the pixel, a refined pixel value of the reference point of the pixel is determined. For example, based on the filtered pixel value of the reference point of the pixel, the original pixel value of the reference point of the pixel, the third filtering threshold value, the fourth filtering threshold value, the third filtering offset value, and the fourth filtering offset value, a refined pixel value of the reference point of the pixel is determined. The third filtering threshold value and the fourth filtering threshold value may be opposite numbers to each other.

[000204] In some embodiments of the invention, if the current pixel point satisfies only the condition for enabling the common filtering mode, but does not satisfy the condition for enabling the extended filtering mode, steps S31 and S32 are performed to take the filtered pixel value as the target pixel value (the final pixel value of the deblocking filtering process). If the current pixel point satisfies both the condition for enabling the common filtering mode and the condition for enabling the extended filtering mode, steps S31-S34 are performed to take the refined pixel value as the target pixel value (the final pixel value of the deblocking filtering process).

[000205] In steps S33 and S34, advanced filtering processing may be performed on the original pixel value of the pixel point based on the filtered pixel value and the unfiltered original pixel value, namely, advanced filtering processing is performed on the original pixel value of the pixel point to obtain a refined pixel value filtered by advanced filtering, so that the refined pixel value filtered by advanced filtering is closer to the real pixel than the filtered pixel value. Therefore, the filtered pixel value is avoided from being much larger or much smaller than the real pixel of the pixel point due to excessive filtering, which improves the image quality.

[000206] In some embodiments of the invention, for step S33, if the difference between the filtered pixel value of the current pixel point and the original pixel value of the current pixel point is greater than the first filtering threshold, the adjusted pixel value of the current pixel point may be determined based on the filtered pixel value of the current pixel point, the original pixel value of the current pixel point, and the first filtering offset value. If the difference between the filtered pixel value of the current pixel point and the original pixel value of the current pixel point is less than the second filtering threshold, the adjusted pixel value of the current pixel point may be determined based on the filtered pixel value of the current pixel point, the original pixel value of the current pixel point, and the second filtering offset value.

[000207] For example, it is assumed that Y ₁ (i) represents the original pixel value of the current pixel point, Y ₂ (i) represents the filtered pixel value of the current pixel point, Y ₃ (i) represents the refined pixel value of the current pixel point, and Y _v (i) = (Y ₁ (i) + Y ₂ (i) + 1) >> 1.

[000208] Thus, if Y ₁ (i) - Y ₂ (i) > T _v , then Y ₃ (i) = Clip (Y _v (i) + f 0 _v ); if (Y ₁ (i) - Y ₂ (i) < N T _v , then Y ₃ (i) = Clip (Y _v (i) + f 1 _v ). In the above formulas, T _v represents the first filtering threshold value, f 0 _v represents the first filtering offset value, N T _v represents the second filtering threshold value, f 1 _v represents the second filtering offset value, N T _v is usually set to - T _v or another value, clip (x) represents x within a predetermined range of values, which is usually [0, 2 ^D - 1], where D is the bit depth of the image. For an 8-bit image, the range is [0, 255], and for a 10-bit image, it is [0, 1023].

[000209] In order to prevent the refined pixel value filtered by the advanced filtering from exceeding the pixel value range, when the refined pixel value is obtained, the refined pixel value may be clipped to a predetermined value range by a Clip operation. When the refined pixel value exceeds the upper limit of the predetermined value range, the refined pixel value is set equal to the upper limit of the predetermined value range; when the refined pixel value is less than the lower limit of the predetermined value range, the refined pixel value is set equal to the lower limit of the predetermined value range. For example, for an 8-bit image, when the refined pixel value is less than 0, the refined pixel value is set equal to 0; when the refined pixel value is greater than 255, the refined pixel value is set equal to 255.

[000210] In some embodiments of the invention, for step S34, if the difference between the filtered pixel value of the reference point of the pixel and the original pixel value of the reference point of the pixel exceeds the third filtering threshold, the adjusted pixel value of the reference point of the pixel is determined based on the filtered pixel value of the reference point of the pixel, the original pixel value of the reference point of the pixel, and the third filtering offset value. If the difference between the filtered pixel value of the reference point of the pixel and the original pixel value of the reference point of the pixel is less than the fourth filtering threshold, the adjusted pixel value of the reference point of the pixel is determined based on the filtered pixel value of the reference point of the pixel, the original pixel value of the reference point of the pixel, and the fourth filtering offset value. The method for determining the adjusted pixel value of the reference point of the pixel is similar to the method for determining the adjusted pixel value of the current pixel point and will not be repeated here.

[000211] In some embodiments of the invention, the third filtering threshold value and the first filtering threshold value may be the same or different; the third filtering offset value and the first filtering offset value may be the same or different; the fourth filtering threshold value and the second filtering threshold value may be the same or different; and the fourth filtering offset value and the second filtering offset value may be the same or different.

[000212] In one possible implementation, for a decoder, a first filtering threshold value, a first filtering offset value, a second filtering offset value, a third filtering threshold value, a third filtering offset value, and a fourth filtering offset value corresponding to a current block can be analyzed from a high-level syntax. Since the first filtering threshold value and the second filtering threshold value are opposite numbers to each other, and the third filtering threshold value and the fourth filtering threshold value are opposite numbers to each other, the decoder can determine the second filtering threshold value and the fourth filtering threshold value.

[000213] In another possible implementation, for a decoder, the first filtering threshold value, the first filtering offset value, the second filtering offset value, the fourth filtering threshold value, the third filtering offset value, and the fourth filtering offset value corresponding to the current block can be analyzed from a high-level syntax. Since the first filtering threshold value and the second filtering threshold value are opposite numbers to each other, and the third filtering threshold value and the fourth filtering threshold value are opposite numbers to each other, the decoder can determine the second filtering threshold value and the third filtering threshold value.

[000214] In another possible implementation, for a decoder, the second filtering threshold value, the first filtering offset value, the second filtering offset value, the third filtering threshold value, the third filtering offset value, and the fourth filtering offset value corresponding to the current block can be analyzed from a high-level syntax. Since the first filtering threshold value and the second filtering threshold value are opposite numbers to each other, and the third filtering threshold value and the fourth filtering threshold value are opposite numbers to each other, the decoder can determine the first filtering threshold value and the fourth filtering threshold value.

[000215] In one possible implementation, for a decoder, the second filtering threshold value, the first filtering offset value, the second filtering offset value, the fourth filtering threshold value, the third filtering offset value, and the fourth filtering offset value corresponding to the current block can be analyzed from a high-level syntax. Since the first filtering threshold value and the second filtering threshold value are opposite numbers to each other, and the third filtering threshold value and the fourth filtering threshold value are opposite numbers to each other, the decoder can determine the first filtering threshold value and the third filtering threshold value.

[000216] In another possible implementation for the decoder, the first filtering threshold value (or the second filtering threshold value, or the third filtering threshold value, or the fourth filtering threshold value, namely, the other three filtering threshold values can be obtained from one filtering threshold value), the first filtering offset threshold value (or the third filtering offset value), the second filtering offset value (or the fourth filtering offset value) corresponding to the current block can be analyzed from a high-level syntax. Therefore, since the first filtering threshold value and the second filtering threshold value are opposite numbers to each other, the second filtering threshold value can be determined. Since the first filtering threshold value and the third filtering threshold value are the same, the third filtering threshold value can be determined. Since the third filtering offset value and the first filtering offset value are the same, the third filtering offset value can be determined. Since the fourth filtering offset value and the second filtering offset value are the same, the fourth filtering offset value can be determined. Since the third filtering threshold value and the fourth filtering threshold value are opposite numbers to each other, the fourth filtering threshold value can be determined.

[000217] Of course, the above are only a few examples, which are not limited here, provided that the decoder can obtain the first filtering threshold value, the second filtering threshold value, the third filtering threshold value, the fourth filtering threshold value, the first filtering offset value, the second filtering offset value, the third filtering offset value and the fourth filtering offset value. The above-mentioned values can be obtained by analysis or inference.

[000218] In the above embodiment of the invention, the high-level syntax includes, but is not limited to, one of the following syntaxes: SPS high-level syntax, PPS high-level syntax, image header high-level syntax, image high-level syntax, slice header high-level syntax, CTU high-level syntax, and CU high-level syntax. Of course, the above are only a few examples of high-level syntaxes, and the types of high-level syntaxes are not limited here, as long as the filtering threshold values and filtering offset values corresponding to the current block can be carried by the high-level syntaxes.

[000219] In the above embodiment of the invention, the pixel value of the current pixel point in the current block may be a luminance component or a chrominance component.

[000220] In one possible implementation, the extended filtering mode enable flag indicates whether to enable the extended filtering mode. If the extended filtering mode enable flag allows the current block to enable the extended filtering mode, it is required to determine whether the current pixel point in the current block satisfies the condition for enabling the extended filtering mode. If the current pixel point satisfies the condition for enabling the extended filtering mode, the original pixel value of the current pixel point is adjusted based on the extended filtering mode. If the extended filtering mode enable flag prohibits the current block from enabling the extended filtering mode, it is directly determined that each pixel point in the current block does not satisfy the condition for enabling the extended filtering mode, and the original pixel value of the current pixel point is not adjusted based on the extended filtering mode. Therefore, if the extended filtering mode enable flag corresponding to the current block allows the current block to enable the extended filtering mode, it is determined whether the current pixel point in the current block satisfies the condition for enabling the extended filtering mode. If the advanced filtering mode enable flag corresponding to the current block prohibits the current block from enabling the advanced filtering mode, it is determined that each pixel point in the current block does not satisfy the advanced filtering mode enable condition.

[000221] For example, for a decoder, the extended filter mode enable flag corresponding to the current block can be analyzed from a high-level syntax. For example, if the extended filter mode enable flag is the first value (e.g., 1), this indicates that the extended filter mode enable flag allows the current block to enable the extended filter mode; if the extended filter mode enable flag is the second value (e.g., 0), this indicates that the extended filter mode enable flag prohibits the current block from enabling the extended filter mode.

[000222] In the above embodiment of the invention, the high-level syntax includes, but is not limited to, one of the following syntaxes: SPS high-level syntax, PPS high-level syntax, image header high-level syntax, image high-level syntax, slice header high-level syntax, CTU high-level syntax, and CU high-level syntax. Of course, the above are only a few examples of high-level syntaxes, and the types of high-level syntaxes are not limited here, as long as the extended filter mode enable flag corresponding to the current block can be carried by the high-level syntaxes.

[000223] Embodiment 8 of the invention: when the condition for turning on the common filtering mode is met, deblocking filtering can be performed on the original pixel value of the pixel point based on the DBF filtering mode (deblocking filtering mode). Since the DBF filtering includes vertical DBF filtering and horizontal DBF filtering, deblocking filtering can be performed on the original pixel value of the pixel point in the following steps.

[000224] In step 1, the filtered pixel value Y ₂ {i) is obtained by performing vertical DBF filtering on the original pixel value Y ₁ (i).

[000225] In step 2, the filtered value Y ₃ (i) of the pixel is obtained by performing horizontal DBF filtering of the value Y ₂ (i) of the pixel.

[000226] In some embodiments of the invention, if only vertical DBF filtering is performed for a pixel point, only step 1 is performed to obtain a filtered pixel value for the pixel point; if only horizontal DBF filtering is performed for a pixel point, only step 2 is performed to obtain a filtered pixel value of the pixel point, where the Y ₂ (i) pixel value of step 2 is replaced with the original pixel value of the pixel point. If vertical DBF filtering is performed at a pixel point first, and then horizontal DBF filtering is performed at the pixel point, steps 1 and 2 are performed sequentially.

[000227] When the common filtering mode enable condition and the extended filtering mode enable condition are both satisfied, deblocking filtering may be performed on the original pixel value of the pixel point based on the DBF filtering mode (deblocking filtering), and then the filtered pixel value filtered by the deblocking filter is refined. Since the DBF filtering includes vertical DBF filtering and horizontal DBF filtering, deblocking filtering may be performed on the original pixel value of the pixel point, and the pixel value filtered by the deblocking filter is refined in the following steps.

[000228] In step 1, the filtered pixel value Y ₂ {i) is obtained by performing vertical DBF filtering on the original pixel value Y ₁ (i).

[000229] In step 2, the refined value Y ₃ (i) of the pixel is obtained based on Y ₂ (i) - Y ₁ (i).

[000230] In step 3, the filtered value Y ₄ (i) of the pixel is obtained by performing horizontal DBF filtering of the value Y ₃ (i) of the pixel.

[000231] In step 4, the refined value Y ₅ (i) of the pixel is obtained based on Y ₄ (i) - Y ₃ (i).

[000232] In some embodiments of the invention, if only vertical DBF filtering is performed for a pixel point, only steps 1 and 2 are performed to obtain a refined pixel value for the pixel point. If only horizontal DBF filtering is performed for a pixel point, only steps 3 and 4 are performed to obtain a refined pixel value for the pixel point, where the pixel value F ₃ (i) of step 3 is replaced with the original value of the pixel point. If vertical DBF filtering is performed at the pixel point first, and then horizontal DBF filtering is performed at the pixel point, steps 1, 2, 3, and 4 are performed sequentially. If horizontal DBF filtering is performed at the pixel point first, and then vertical DBF filtering is performed at the pixel point, the steps are similar and will not be repeated here.

[000233] In some embodiments of the invention, steps 2 and 4 represent a procedure for processing an advanced filtering mode when the condition for enabling the advanced filtering mode is satisfied, namely a process for adjusting the filtered pixel value to obtain a refined pixel value.

[000234] In step 2, it is assumed that Y _v (i) = (Y ₁ (i) + Y ₂ (i) + 1) >> 1. If V ₁ (i) - Y ₂ (i) > T _v , then Y ₃ (i) = Clip (Y _v (i) + f 0 _v ); if Y ₁ (i) - Y ₂ (i) < N T _v , then F ₃ (i) = Clip (Y _v (i) + f 1 _v ), and otherwise Y ₃ (i) = Y ₂ (i) (in one embodiment, in this case, Y ₃ (i) may be obtained by filtering Y ₂ (i), e.g., Y ₃ (i) = Y ₂ (i) + f 2 _v .

[000235] In some embodiments of the invention, clip(x) represents that x is limited to a predetermined range of image values, which is typically [0, ^2D - 1], where D is the bit depth of the image. For an 8-bit image, the range of image values may be [0, 255]; for a 10-bit image, the range of image values is [0, 1023]. The threshold value NT _v is typically set to - T _v or another value.

[000236] Similar to step 2, in step 4, assuming that Y _h (i) = (Y ₃ (i) + Y ₄ (i) + 1) >> 1, if Y ₄ (i) - Y ₃ (i) > T _{h ,} then Y ₅ (i) = Clip (Y _h (i) + f 0 _h ); if Y ₁ (i) - Y ₂ (i) < NT _h , then Y ₅ (i) = Clip (Y _h (i) + , and otherwise Y ₅ (i) = Y ₄ (i) (in one embodiment, in this case, Y ₅ (i) may be obtained by filtering Y ₄ (i), such that Y ₅ (i) = Y ₄ (i) + f 2 _h , where NT _h is typically set to - T _h or another value.

[000237] In the above embodiment, Tv and NTv represent filtering threshold values, f0v, f1v and f2v represent filtering offset values, and clip(x) is a value x limited within a predetermined range of values. For example, Tv refers to the above-mentioned first filtering threshold value and the third filtering threshold value (for example, the first filtering threshold value and the third filtering threshold value are the same), NTv refers to the above-mentioned second filtering threshold value and the fourth filtering threshold value (for example, the second filtering threshold value and the fourth filtering threshold value are the same), f0v refers to the above-mentioned first filtering offset value and the third filtering offset value (for example, the first filtering offset value and the third filtering offset value are the same), and f1v refers to the above-mentioned second filtering offset value and the fourth filtering offset value (for example, the second filtering offset value and the fourth filtering offset value are the same). NTv=-Tv, where Tv and NTv are numbers opposite to each other.

[000238] In the above embodiment of the invention, Th and NTh are filtering threshold values, f0h, f1h and f2h are filtering offset values, and clip(x) represents that the value x is limited within a predetermined range of values. For example, Th refers to the above-mentioned first filtering threshold value and the third filtering threshold value (for example, the first filtering threshold value and the third filtering threshold value are the same), NTh refers to the above-mentioned second filtering threshold value and the fourth filtering threshold value (for example, the second filtering threshold value and the fourth filtering threshold value are the same), f0h refers to the above-mentioned first filtering offset value and the third filtering offset value (for example, the first filtering offset value and the third filtering offset value are the same), and f1h refers to the above-mentioned second filtering offset value and the fourth filtering offset value (for example, the second filtering offset value and the fourth filtering offset value are the same). NTh=-Th, where Th and NTh are numbers opposite to each other.

[000239] Embodiment 9 of the invention: in DBF, if filtering is performed only based on a set rule, there will be overfiltering or underfiltering. For example, if the reconstruction value before DBF is Y1, and the pixel value after DBF is Y2, classification can be performed based on Y2-Y1. Classification based on the filtering residual has the following main advantages: for some pixel values subjected to overfiltering or pseudofiltering, a special expansion can be performed to make the pixels of these classes closer to the original value. Overfiltering refers to the fact that Y2 is much larger (or much smaller) than Y1, and therefore Y2 is much larger (or much smaller) than the original pixel value. Pseudofiltering refers to the fact that Y2-Y1 is 0 or close to 0, namely, these pixel values remain unchanged after filtering, so that the filtering effect cannot be achieved. For the above-mentioned detection in the present embodiment of the invention, the pixel value of the pixel point may be refined based on the extended refinement mode, namely, if the extended refinement mode is turned on for the current pixel point in the current block, the original pixel value of the current pixel point is refined based on the extended refinement mode, and not the general filtering mode or the extended filtering mode.

[000240] In one possible implementation, the process of refining the original pixel value may include the following steps.

[000241] In step 1, the filtered pixel value Y ₂ (i) is obtained by performing vertical DBF filtering on the original pixel value Y ₁ (i).

[000242] In step 2, a refined pixel value F ₃ (i) is obtained based on Y ₂ (i) - Y ₁ (i).

[000243] In step 3, a filtered value Y ₄ (i) of the pixel is obtained by performing horizontal DBF filtering of the value Y ₃ (i) of the pixel.

[000244] In step 4, a refined value of the pixel Y ₅ (i) is obtained based on Y ₄ (i) - Y ₃ (i).

[000245] In step 2, the following two cases are possible: abs(Y ₂ (i) - Y _i (i)) < the threshold value and abs(Y ₂ (i) - Y ₁ (i)) is not less than the threshold value. If abs(Y ₂ (i) - Y ₁ (i)) < the threshold value, the following two cases may occur: BS is equal to 0 and BS is greater than 0. In some embodiments of the invention, the threshold value may be the above-mentioned first filtering threshold value or the second filtering threshold value, where, for example, the first filtering threshold value and the second filtering threshold value are numbers that are opposite to each other. If the first filtering threshold value is a positive value, the threshold value may be the first filtering threshold value; if the second filtering threshold value is a positive value, the threshold value may be the second filtering threshold value.

[000246] Finally, the process of refining the original pixel value may include the following three cases.

[000247] Case 1: When BS is 0, filtering is not performed (i.e., Y ₂ (i) is equal to which is equivalent to not performing vertical DBF filtering of the original pixel value Y ₁ (i), namely, not performing step 1), but the original pixel value Y ₁ (i) may be refined based on the advanced refinement mode to obtain a refined pixel value.

[000248] Case 2: when BS is greater than 0 and abs(Y ₂ (i) - Y ₁ (i) < the threshold value, filtering may be performed (i.e., performing vertical DBF filtering of the original pixel value, namely, performing step 1). Based on the performance of step 1, the filtered pixel value Y ₂ (i) may be refined based on the advanced filtering mode to obtain a refined pixel value F ₃ (i) of the pixel point.

[000249] Case 3: when BS is greater than 0 and abs(Y ₂ (i) - Y ₁ (i) is not less than the threshold value, filtering (i.e., performing vertical DBF filtering of the original value Y^ii) of the pixel may be performed, namely, performing step 1). Based on the performance of step 1, the filtered pixel value Y ₂ (i) is no longer refined based on the advanced filtering mode, namely, step 2 is no longer performed, namely, Y ₃ (i) = Y ₂ (i).

[000250] At step 4, the following two cases are possible: abs(Y ₄ (i) - Y ₃ (i)) < the threshold value and abs(Y ₄ (i) - Y ₃ (i)) is not less than the threshold value. If abs(Y ₄ (i) - Y ₃ (i)) < the threshold value, then the following two more cases are possible: BS is equal to 0 and BS is greater than 0.

[000251] Finally, the process of refining the original pixel value may include the following three cases.

[000252] Case 1: When BS is 0, filtering is not performed (i.e., F ₄ (i) is equal to Y ₃ {i), which is equivalent to not performing horizontal DBF filtering of the original pixel value Y ₃ (i), namely, not performing step 3), but the original pixel value Y ₃ (i) may be refined based on the advanced refinement mode to obtain a refined pixel value.

[000253] Case 2: when BS is greater than 0 and abs(Y ₄ (i) - Y ₃ (i)) < a threshold value, filtering may be performed (i.e., performing horizontal DBF filtering on the original pixel value F ₃ (i), namely, performing step 3). Based on the performance of step 3, the filtered pixel value Y ₄ (i) of the pixel point may be refined based on the advanced filtering mode to obtain a refined pixel value Y ₅ (i) of the pixel point.

[000254] Case 3: When BS is greater than 0 and abs(Y ₄ (i) - Y ₃ (i)) is not less than the threshold value, filtering may be performed (i.e., performing horizontal DBF filtering for the original pixel value Y ₃ (i), namely, performing step 3). Based on the performance of step 3, the filtered pixel value Y ₄ (i) is not corrected based on the advanced filtering mode, namely, step 4 is not performed, namely, Y ₅ (i) = Y ₄ (i)

[000255] Finally, if BS is 0, the processing is performed based on the advanced refinement mode, namely, filtering may not be performed, that is, Y ₂ (i) = Y ₁ (i) and Y ₄ (i) = Y ₃ (i). Based on this, Y ₁ (i) can be refined based on the advanced refinement mode, and Y ₃ (i) can also be refined based on the advanced refinement mode. Therefore, DBF filtering can be performed in the following steps.

[000256] In step 1, a filtered value Y ₂ {i) of the pixel is obtained by performing vertical DBF filtering of the original value Y ₁ (i) of the pixel.

[000257] In step 2, if BS is 0, Y ₁ (i) is refined based on the extended refinement mode to obtain the refined pixel value Y ₃ (i). If BS is greater than 0 and abs(Y ₂ (i) - Y ₁ (i) << the threshold, the extended filtering mode is turned on to obtain the refined pixel value Y ₃ (i) based on Y ₂ (i) - Y ₁ (i), as shown in step 2 of embodiment 8 of the invention. If BS is greater than 0 and abs(Y ₂ (i) - Y ₁ (i)) is not less than the threshold, the general filtering mode is turned on to no longer perform refinement of the filtered pixel value Y ₂ {i), namely Y ₃ (i) = Y ₂ (i).

[000258] In some embodiments of the invention, if BS is 0, the step is not actually performed, namely, it is not necessary to obtain the filtered value Y ₂ (i) of the pixel.

[000259] In step 3, the filtered value Y ₄ (i) of the pixel is obtained by performing horizontal DBF filtering of the value Y ₃ (i) of the pixel.

[000260] In step 4, if BS is 0, Y ₃ (i) is refined based on the extended refinement mode to obtain the refined pixel value Y ₅ (i). If BS is greater than 0 and abs(Y ₄ (i) - Y ₃ (i)) < the threshold, the extended filtering mode is turned on to obtain the refined pixel value Y ₅ (i) based on Y ₄ (i) - Y ₃ (i), as shown in step 4 of embodiment 8 of the invention. If BS is greater than 0 and abs(Y ₄ (i) - Y ₃ (i)) is not less than the threshold, the general filtering mode is turned on to no longer refine the filtered pixel value Y ₄ (i), namely Y ₅ (i) = Y ₄ (i)

[000261] In some embodiments of the invention, if BS is 0, step 3 is not actually performed, namely, it is not necessary to obtain the filtered value Y ₄ (i) of the pixel.

[000262] In another possible implementation, if BS is greater than 0, filtering is performed, but abs(Y ₂ (i) - Y ₁ (i) < the threshold value after filtering. In this case, an advanced filtering mode is used for processing, namely, DBF filtering can be performed in the following stages.

[000263] In step 1, a filtered value Y2(0) of the pixel is obtained by performing vertical DBF filtering on the original value _Y1 (i) of the pixel.

[000264] In step 2, if BS is greater than 0 when abs(Y ₂ (i) - Y ₁ (i) < the threshold value is still satisfied after performing vertical DBF filtering for Y ₁ (i), a refined pixel value Y ₃ (i) is obtained based on the advanced filtering mode. For example, Y ₃ (i) is obtained as Y ₁ (i) plus a compensation value. Otherwise, if abs(Y ₂ (i) - Y ₁ (i) is not less than the threshold value, Y ₃ (i) = Y ₂ (i).

[000265] In step 3, a filtered value Y ₄ (i) of the pixel is obtained by performing horizontal DBF filtering of the value Y ₃ (i) of the pixel.

[000266] In step 4, if BS is greater than 0 when abs(Y ₄ (i) - Y ₃ (i)) < the threshold value is still satisfied after performing horizontal DBF filtering for Y ₃ {i), a refined pixel value Y ₅ (i) is obtained based on the advanced filtering mode. For example, Y ₅ (i) is obtained as Y ₃ (i) plus a compensation value. Otherwise, if abs(Y ₄ (i) - Y ₃ (i)) is not less than the threshold value, then Y ₅ (i) = Y ₄ (i).

[000267] Embodiment 10 of the invention: for embodiment 9 of the invention, if BS is 0, Y ₁ (i) is refined based on the extended refinement mode to obtain the refined pixel value Y ₃ (i). The specific refinement process may be provided in the following steps. If BS is 0, Y ₃ (i) is refined based on the extended refinement mode to obtain the refined pixel value Y ₅ (i). This process is similar to the process of obtaining the refined pixel value Y ₃ (i) and therefore will not be repeated here.

[000268] First, a gradient value Y ₁ (i) is determined, where Y ₁ (i) may be an original pixel value of the current pixel point or an original pixel value of the reference pixel point. For a vertical boundary, a horizontal gradient value DY ₁ (i) may be calculated for Y ₁ (i); for a horizontal boundary, a vertical gradient value DY ₁ (i) may be calculated for Y ₁ (i). For example, if pi and qi respectively represent an original pixel value of the current pixel point and an original pixel value of the reference pixel point (corresponding to Y ₁ (i)), a gradient value DP0 of the original pixel value pi of the current pixel point is calculated according to the following formula: DP0=(pi - qi + 2) >>2; the gradient value DQ0 of the initial pixel value qi of the pixel reference point is calculated using the following formula: DQ0=(qi - pi + 2)>>2.

[000269] Next, based on the size of DY ₁ (i), Y ₃ (i) is obtained by refining the compensation. For example, the refined value Pi of the pixel corresponding to the original value pi of the current pixel point is determined as follows: if DPi>alt_dbr_th, then Pi=clip(pi + alt_dbr_offset0); if DPi<alt_dbr_th, then Pi=clip(pi + alt_dbr_offset1), where i is 0, 1, 2, etc. The refined value Qi of the pixel corresponding to the original value qi of the pixel reference point is determined as follows: if DQi>alt_dbr_th, then Qi=clip(qi + alt_dbr_offset0); if DQi<-alt_dbr_th, then Qi=clip(qi + alt_dbr_offset1), where i is 0, 1 or 2.

[000270] In the above formulas, alt_dbr_th refers to the first refinement threshold value and the third refinement threshold value (for example, the third refinement threshold value and the first refinement threshold value are the same), alt_dbr_offset0 refers to the first refinement offset value and the third refinement offset value (for example, the first refinement offset value and the third refinement offset value are the same), alt_dbr_offset1 refers to the second refinement offset value and the fourth refinement offset value (for example, the second refinement offset value and the fourth refinement offset value are the same), -alt_dbr_th refers to the second refinement threshold value and the fourth refinement threshold value (for example, the second refinement threshold value and the fourth refinement threshold value are the same), and -alt_dbr_th and alt_dbr_th are opposite numbers to each other.

[000271] Embodiment 11 of the invention: the extended refinement mode is controlled so that it is enabled by a high-level syntax (for example, a high-level syntax of SPS). For example, the adbr_enable_flag flag is encoded/decoded in the sequence header, namely, the encoder encodes the adbr_enable_flag flag in the sequence header, and the decoder decodes the adbr_enable_flag flag in the sequence header, adbr_enable_flag is a binary variable, wherein the value "1" indicates the availability of the extended refinement mode, and the value "0" indicates that the extended refinement mode is not available. The value of AdbrEnableFlag is adbr_enable_flag. If there is no adbr_enable_flag in the bitstream, the value of AdbrEnableFlag is 0.

[000272] Finally, for the decoder, the extended refinement mode enable flag (i.e., AdbrEnableFlag) corresponding to the current block can be parsed from the high-level syntax. If the value of the extended refinement mode enable flag is 1, this indicates that the extended refinement mode enable flag allows the current block to enable the extended refinement mode; if the value of the extended refinement mode enable flag is 0, this indicates that the extended refinement mode enable flag prohibits the current block from enabling the extended refinement mode.

[000273] Embodiment 12 of the invention: the extended filtering mode and the extended refinement mode are controlled simultaneously so that they can be enabled using a high-level syntax (e.g., a high-level syntax of SPS). For example, the flag dbr_enable_flag is encoded/decoded in the sequence header, namely, the encoder encodes the flag dbr_enable_flag in the sequence header, and the decoder decodes the flag dbr_enable_flag in the sequence header.

[000274] dbr_enable_flag is a binary variable where a value of 1 indicates that the advanced filtering mode is used and the advanced refinement mode is enabled, and a value of 0 indicates that the advanced filtering mode is used and the advanced refinement mode is disabled. The value of DbrEnableFlag is equal to dbr_enable_flag. If dbr_enable_flag is not present in the bitstream, the value of DbrEnableFlag is equal to 0.

[000275] Finally, for the decoder, the extended filtering mode enable flag and the extended refinement mode enable flag (i.e., DbrEnableFlag, which is used as the extended filtering mode enable flag and the extended refinement mode enable flag at the same time) corresponding to the current block can be parsed from the high-level syntax. If the value of DbrEnableFlag is 1, it indicates that the current block is allowed to enable the extended filtering mode and the extended refinement mode; if the value of DbrEnableFlag is 0, it indicates that the current block is prohibited from enabling the extended filtering mode and the extended refinement mode.

[000276] Embodiment 13 of the invention: Reference can be made to Table 1 to express a high-level syntax (e.g., a high-level syntax of an image header), such as the encoding/decoding syntax of an image header shown in Table 1. The encoder encodes the syntax shown in Table 1 in the image header, and the decoder decodes the syntax shown in Table 1 in the image header.

[000277] The meanings of the corresponding syntaxes in Table 1 are described below.

[000278] The picture-level vertical deblocking filtering refinement enable flag is represented as picture_dbr_v_enable_flag, which is a binary variable where a value of "1" indicates that the current picture enables the use of vertical deblocking filtering refinement, and a value of "0" indicates that the current picture prohibits the use of vertical deblocking filtering refinement. The value of PictureDbrVEnableFlag is equal to the value of picture dbr v enable flag. If picture_dbr_v_enable_flag is not present in the bitstream, the value of PhDbrVEnableFlag is equal to 0.

[000279] In some embodiments of the invention, for the advanced refinement mode, PictureDbrVEnableFlag corresponds to the advanced refinement mode enable flag and is the advanced refinement mode enable flag for vertical DBF filtering. In other words, when vertical DBF filtering is to be performed, PictureDbrVEnableFlag indicates whether the advanced refinement mode is enabled or whether the advanced refinement mode is prohibited.

[000280] In some embodiments of the invention, for the advanced filtering mode, PictureDbrVEnableFlag corresponds to the advanced filtering mode enable flag and is the advanced filtering mode enable flag for vertical DBF filtering. In other words, when vertical DBF filtering is to be performed, PictureDbrVEnableFlag indicates whether the advanced filtering mode is allowed to be enabled or whether the advanced filtering mode is prohibited to be enabled.

[000281] Finally, PictureDbrVEnableFlag may represent a flag for enabling the advanced refinement mode for vertical DBF filtering and a flag for enabling the advanced filtering mode for vertical DBF filtering. In other words, the flag for enabling the advanced refinement mode and the flag for enabling the advanced filtering mode have the same flag, namely, the current picture allows enabling the advanced refinement mode and the advanced filtering mode at the same time, or prohibits enabling the advanced refinement mode and the advanced filtering mode at the same time.

[000282] The vertical refinement threshold for deblocking filtering is represented as dbr_v_threshold_minus1 and is used to determine the vertical refinement threshold for deblocking filtering of the current image, where the threshold is in the range from 0 to 1. The value of DbrVThreshold is equal to the value of dbr_v_threshold_minus1 + 1. If dbr_v_threshold_minus1 is not present in the bitstream, the value of DbrVThreshold is 0.

[000283] In some embodiments of the invention, for the advanced refinement mode, DbrVThreshold corresponds to the first refinement threshold value (for example, the third refinement threshold value and the first refinement threshold value are the same) and is the first refinement threshold value for vertical DBF filtering. In other words, when vertical DBF filtering is to be performed, DbrVThreshold represents the first refinement threshold value in the above-described embodiment of the invention. In addition, the second refinement threshold value (for example, the fourth refinement threshold value and the second refinement threshold value are the same) and the first refinement threshold value in the above-described embodiment of the invention are opposite numbers to each other, and thus the second refinement threshold value can be determined based on DbrVThreshold.

[000284] In some embodiments of the invention, for the advanced filtering mode, DbrVThreshold corresponds to the first filtering threshold value (for example, the third filtering threshold value and the first filtering threshold value are the same) and is the first filtering threshold value for the vertical DBF filtering. In other words, when the vertical DBF filtering is to be performed, DbrVThreshold represents the first filtering threshold value in the above embodiment of the invention. In addition, the second filtering threshold value (for example, the fourth filtering threshold value and the second filtering threshold value are the same) in the above embodiment of the invention and the first filtering threshold value are opposite numbers to each other, and thus the second filtering threshold value can be determined based on DbrVThreshold.

[000285] Finally, DbrVThreshold may represent a first refinement threshold value and a first filtering threshold value for vertical DBF filtering, and in other words, the first refinement threshold value and the first filtering threshold value are the same and may have the same value.

[000286] Deblocking Filtering Vertical Refinement Offset 0 Value (dbr_v_offset0_minus1) is used to determine the deblocking filtering vertical refinement offset 0 value of the current image, which takes a value from 0 to 3. The DbrVOffsetO value is a negative value, which is the opposite of the result of the sum of dbr_v_offset0_minus1 + 1. If dbr_v_offset0_minus1 is not present in the bitstream, the DbrVOffsetO value is 0.

[000287] In some embodiments of the invention, for the advanced filtering mode, DbrVOffsetO corresponds to the first filtering offset value (for example, the third filtering offset value and the first filtering offset value are the same) and is the first filtering offset value for vertical DBF filtering. When vertical DBF filtering is to be performed, DbrVOffsetO represents the first filtering offset value in the embodiment of the invention described above.

[000288] Deblocking Filtering Vertical Refinement Offset 1 Value (dbr_v_offset0_minus1) is used to determine the deblocking filtering vertical refinement offset 1 value of the current image, which takes values from 0 to 3. The value of DbrVOffset1 is equal to the value of dbr_v_offset1_minus1 + 1. If dbr_v_offset1_minus1 is not present in the bitstream, the value of DbrVOffsetl is equal to 0.

[000289] In some embodiments of the invention, for the advanced filtering mode, DbrVOffsetl corresponds to the second filtering offset value (for example, the fourth filtering offset value and the second filtering offset value are the same) and is the second filtering offset value for vertical DBF filtering. When vertical DBF filtering is to be performed, DbrVOffsetl represents the second filtering offset value in the embodiment of the invention described above.

[000290] Advanced Deblocking Filtering Vertical Refinement Offset 0 Value (dbr_v_alt_offset0_minus1) is used to determine the offset value 0 of the current image deblocking filtering vertical refinement when the BS value is 0, and the value of dbr_v_alt_offset0_minus1 is between 0 and 3. The value of DbrVAltOffset0 is a negative value that is the opposite of the result of the sum of dbr_v_alt_offset0_minus1 + 1. If there is no dbr_v_alt_offset0_minus1 in the bitstream, the value of DbrVAltOffsetO is 0.

[000291] In some embodiments of the invention, for the advanced refinement mode, DbrVAltOffsetO corresponds to the first refinement offset value (for example, the third refinement offset value and the first refinement offset value are the same) and is the first refinement offset value for vertical DBF filtering. When vertical DBF filtering is to be performed, DbrVAltOffsetO represents the first refinement offset value in the embodiment of the invention described above.

[000292] The Advanced Deblocking Filtering Vertical Refinement Offset 1 Value (dbr_v_alt_offset0_minus1) is used to determine the offset 1 value of the deblocking filtering vertical refinement of the current image when the BS value is 0, where the value of dbr_v_alt_offset0_minus1 is between 0 and 3. The value of DbrVAltOffsetl is equal to the value of dbr_v_alt_offset0_minus1 + 1. If there is no dbr_v_alt_offset0_minus1 in the bitstream, the value of DbrVAltOffset1 is equal to 0.

[000293] In some embodiments of the invention, for the advanced refinement mode, DbrVAltOffsetl corresponds to the second refinement offset value (for example, the fourth refinement offset value and the second refinement offset value are the same) and is the second refinement offset value for vertical DBF filtering. When vertical DBF filtering is to be performed, DbrVAltOffset1 represents the second refinement offset value in the embodiment of the invention described above.

[000294] The flag for enabling horizontal filtering refinement for deblocking at the picture level is represented as picture_dbr_h_enable_flag, which is a binary variable where the value "1" indicates that the current picture enables the use of horizontal filtering refinement for deblocking, and the value "0" indicates that the current picture does not enable the use of horizontal filtering refinement for deblocking. The value of PhDbrHEnableFlag is equal to the value of picture_dbr_h_enable_flag. If picture_dbr_h_enable_flag is not present in the bitstream, the value of PhDbrHEnableFlag is equal to 0.

[000295] In some embodiments of the invention, for the extended refinement mode, PhDbrHEnableFlag corresponds to the extended refinement mode enable flag and is the extended refinement mode enable flag for horizontal DBF filtering. In other words, when horizontal DBF filtering is to be performed, PhDbrHEnableFlag indicates whether the extended refinement mode is enabled or disabled.

[000296] In some embodiments of the invention, for the advanced filtering mode, PhDbrHEnableFlag corresponds to the advanced filtering mode enable flag and is the advanced filtering mode enable flag for horizontal DBF filtering. In other words, when horizontal DBF filtering is to be performed, PhDbrHEnableFlag indicates whether the advanced filtering mode is allowed to be enabled or whether the advanced filtering mode is prohibited to be enabled.

[000297] Finally, PhDbrHEnableFlag may represent a flag for enabling the advanced refinement mode for horizontal DBF filtering and a flag for enabling the advanced filtering mode for horizontal DBF filtering. In other words, the flag for enabling the advanced refinement mode and the flag for enabling the advanced filtering mode share the same flag, namely, the current image allows enabling the advanced refinement mode and the advanced filtering mode at the same time, or prohibits enabling the advanced refinement mode and the advanced filtering mode at the same time.

[000298] The horizontal refinement threshold for deblocking filtering is represented as dbr_h_threshold_minus1, which is used to determine the horizontal refinement threshold for deblocking filtering of the current image, where the threshold value takes a value between 0 and 1. The value of DbrHThreshold is equal to the value of dbr_h_threshold_minus_1 + 1. If dbr_h_threshold_minus_1 is not present in the bitstream, the value of DbrHThreshold is equal to 0.

[000299] In some embodiments of the invention, for the advanced refinement mode, DbrHTreshold corresponds to the first refinement threshold value (for example, the third refinement threshold value and the first refinement threshold value are the same) and is the first refinement threshold value for horizontal DBF filtering. In other words, when horizontal DBF filtering is to be performed, DbrHThreshold represents the first refinement threshold value in the embodiment of the invention described above. In addition, the second refinement threshold value (for example, the fourth refinement threshold value and the second refinement threshold value are the same) in the embodiment of the invention described above and the first refinement threshold value are opposite numbers to each other, and thus the second refinement threshold value can be determined based on DbrHThreshold.

[000300] In some embodiments of the invention, for the advanced filtering mode, DbrHTreshold corresponds to the first filtering threshold value (for example, the third filtering threshold value and the first filtering threshold value are the same) and is the first filtering threshold value for horizontal DBF filtering. In other words, when horizontal DBF filtering is to be performed, DbrHThreshold represents the first filtering threshold value in the embodiment of the invention described above. In addition, the second filtering threshold value (for example, the fourth filtering threshold value and the second filtering threshold value are the same) in the embodiment of the invention described above and the first filtering threshold value are opposite numbers to each other, and thus the second filtering threshold value can be determined based on DbrHThreshold.

[000301] Finally, DbrHTreshold may represent a first refinement threshold value and a first filtering threshold value for horizontal DBF filtering, namely, the first refinement threshold value and the first filtering threshold value are the same and have the same value.

[000302] The horizontal refinement offset 0 value of deblocking filtering (dbr_h_offset0_minus1) is used to determine the offset 0 value of the horizontal refinement offset 0 of the current image, where the offset value is in the range from 0 to 3. The value of DbrHOffsetO is a negative value, which is the opposite number of the result of the sum of dbr_h_offset0_minus1 + 1. If dbr_h_offset0_minus1 is not present in the bitstream, the value of DbrHOffsetO is 0.

[000303] In some embodiments of the invention, for the advanced filtering mode, DbrHOffsetO corresponds to the first filtering offset value (for example, the third filtering offset value and the first filtering offset value are the same) and is the first filtering offset value for horizontal DBF filtering. When horizontal DBF filtering is to be performed, DbrHOffsetO represents the first filtering offset value in the embodiment of the invention described above.

[000304] The Deblocking Filtering Horizontal Refinement Offset 1 value (dbr_h_offset1_minus1) is used to determine the offset 1 value of the deblocking filtering horizontal refinement of the current image, where the offset value is in the range from 0 to 3. The value of DbrHOffsetl is equal to the value of dbr_h_offset1_minus1 + 1. If dbr_h_offset1_minus1 is not present in the bitstream, the value of DbrHOffsetl is equal to 0.

[000305] In some embodiments of the invention, for the advanced filtering mode, DbrHOffsetl corresponds to the second filtering offset value (for example, the fourth filtering offset value and the second filtering offset value are the same) and is the second filtering offset value for horizontal DBF filtering. In other words, when horizontal DBF filtering is to be performed, DbrHOffsetl represents the second filtering offset value in the embodiment of the invention described above.

[000306] The horizontal refinement offset value 0 of the advanced deblocking filtering (dbr_h_offset0_minus1) is used to determine the offset value 0 of the horizontal refinement of the deblocking filtering of the current image when the BS value is 0, where the value of dbr_h_offset0_minus1 is in the range from 0 to 3. The value of DbrHAltOffset0 is a negative value, which is the opposite number of the result of the sum of dbr_h_offset0_minus1 + 1. If there is no dbr_h_offset0_minus1 in the bitstream, the value of DbrHAltOffset0 is 0.

[000307] In some embodiments of the invention, for the advanced refinement mode, DbrHAltOffset0 corresponds to the first refinement offset value (for example, the third refinement offset value and the first refinement offset value are the same) and is the first refinement offset value for horizontal DBF filtering. In other words, when horizontal DBF filtering is to be performed, DbrHAltOffset0 represents the first refinement offset value in the embodiment of the invention described above.

[000308] The Advanced Deblocking Filtering Horizontal Refinement Offset 1 Value (dbr_h_offset1_minus1) is used to determine the offset value of the horizontal refinement of the deblocking filtering of the current image when the BS value is 0, where the value of dbr_h_offset1_minus1 is between 0 and 3. The value of DbrHAltOffset1 is equal to the value of dbr_h_offset1_minus1 + 1. If there is no dbr_h_offset1_minus1 in the bitstream, the value of DbrHAltOffset1 is equal to 0.

[000309] In some embodiments of the invention, for the advanced refinement mode, DbrHAltOffse1 corresponds to the second refinement offset value (for example, the fourth refinement offset value and the second refinement offset value are the same) and is the second refinement offset value for horizontal DBF filtering. In other words, when horizontal DBF filtering is to be performed, DbrHAltOffsetl represents the second refinement offset value in the embodiment of the invention described above.

[000310] Embodiment 14 of the invention: Reference can be made to Table 2 to express a high-level syntax (e.g., a high-level syntax of an image header), such as the encoding/decoding syntax of an image header shown in Table 2. The encoder encodes the syntax shown in Table 2 into the image header, and the decoder decodes the syntax shown in Table 2 into the image header.

[000311] The meanings of the corresponding syntaxes in Table 2 are described below.

[000312] The picture-level extended vertical refinement enable flag is represented as picture alt_dbr_v_enable_flag, which is a binary variable where a value of "1" indicates that the current picture enables the extended vertical refinement and a value of "0" indicates that the current picture prohibits the extended vertical refinement. The value of PictureAltDbrVEnableFlag is equal to the value of picture_alt_dbr_v_enable_flag. If there is no picture_alt_dbr_v_enable_flag in the bitstream, the value of PhAltDbrVEnableFlag is equal to 0.

[000313] In some embodiments of the invention, for the advanced refinement mode, PictureAltDbrVEnableFlag corresponds to the advanced refinement mode enable flag and is the advanced refinement mode enable flag for vertical DBF filtering. In other words, when vertical DBF filtering is to be performed, PictureAltDbrVEnableFlag indicates whether the advanced refinement mode is allowed to be enabled or whether the advanced refinement mode is prohibited to be enabled.

[000314] Unlike PictureDbrVEnableFlag in embodiment 13 of the invention, PictureAltDbrVEnableFlag is only a flag for enabling the extended refinement mode for vertical DBF filtering, and not a flag for enabling the extended filtering mode for vertical DBF filtering.

[000315] The picture-level extended horizontal refinement enable flag is represented as picture_alt_dbr_h_enable_flag, which is a binary variable where a value of "1" indicates that the current picture enables the extended horizontal refinement and a value of "0" indicates that the current picture prohibits the extended horizontal refinement. The value of PictureAltDbrHEnableFlag is equal to the value of picture picture_alt_dbr_h_enable_flag. If picture_alt_dbr_h_enable_flag is not present in the bitstream, the value of PhAltDbrHEnableFlag is equal to 0.

[000316] In some embodiments of the invention, for the advanced refinement mode, PhAltDbrHEnableFlag corresponds to the advanced refinement mode enable flag and is the advanced refinement mode enable flag for horizontal DBF filtering. In other words, when horizontal DBF filtering is to be performed, PhAltDbrHEnableFlag indicates whether the advanced refinement mode is enabled or whether the advanced refinement mode is prohibited.

[000317] Unlike PictureDbrHEnableFlag in embodiment 13 of the invention, PhAltDbrHEnableFlag is only a flag for enabling the extended refinement mode for horizontal DBF filtering, and not a flag for enabling the extended filtering mode for horizontal DBF filtering.

[000318] The meanings of the other syntaxes in Table 2 are the same as the meanings of the corresponding syntaxes in Table 1 and are therefore not repeated here.

[000319] Embodiment 15 of the invention: For Embodiment 11 of the invention, adbr_enable_flag can be encoded and decoded only when the deblocking filtering mode is enabled. Namely, it can first be determined whether to enable the deblocking filtering mode, and if the deblocking filtering mode is enabled, the adbr_enable_flag flag can be encoded/decoded in the sequence header, and if the deblocking filtering mode is not enabled, the adbr_enable_flag flag is not encoded/decoded in the sequence header. In short, the extended refinement mode (adbr_enable_flag is used to control the enabling of the extended refinement mode) is a submode of the deblocking filtering mode, which is allowed to be enabled only when the deblocking filtering mode is enabled.

[000320] For embodiment 12 of the invention, dbr_enable_flag may be encoded and decoded only when the deblocking filtering mode is enabled. Namely, it may first be determined whether to enable the deblocking filtering mode, and if the deblocking filtering mode is enabled, the dbr_enable_flag flag may be encoded/decoded in the sequence header, and if the deblocking filtering mode is not enabled, the dbr_enable_flag flag is not encoded/decoded in the sequence header. In short, the extended filtering mode (dbr_enable_flag is used to control whether to enable the extended filtering mode) is a submode of the deblocking filtering mode, which is allowed to be enabled only when the deblocking filtering mode is enabled.

[000321] For embodiment 13 of the invention, the high-level syntaxes (used to control the inclusion of the advanced filtering mode and the advanced refinement mode) shown in Table 1 are encoded and decoded only when the deblocking filtering mode is enabled. Namely, it may first be determined whether to include the deblocking filtering mode, and if the deblocking filtering mode is enabled, the high-level syntaxes shown in Table 1 are encoded/decoded in the image header, and if the deblocking filtering mode is not enabled, the high-level syntaxes shown in Table 1 are not encoded/decoded in the image header.

[000322] For embodiment 14 of the invention, the high-level syntaxes (used to control the inclusion of the advanced filtering mode and the advanced refinement mode) shown in Table 2 are encoded and decoded only when the deblocking filtering mode is enabled. Namely, it can first be determined whether the deblocking filtering mode is enabled, and if the deblocking filtering mode is enabled, the high-level syntaxes shown in Table 2 are encoded/decoded in the image header, and if the deblocking filtering mode is not enabled, the high-level syntaxes shown in Table 2 are not encoded/decoded in the image header.

[000323] Embodiment 16 of the invention: for a filtering process for eliminating blockiness of a luminance component (i.e., the current block is a luminance component), for example, the luminance component is refined based on an advanced refinement mode or an advanced filtering mode.

[000324] The DBR parameters of the luminance component are obtained in the following process:

[000325] If the current border to be filtered is a vertical border and the value of PictureDbrVEnableFlag is 1, or the current border to be filtered is a horizontal border and the value of PictureDbrHEnableFlag is 1, the value of PictureDbrEnableFlag is 1; otherwise, the value of PictureDbrEnableFlag is 0. If the current border to be filtered is a vertical border and the value of PictureAltDbrVEnableFlag is 1, or the current border to be filtered is a horizontal border and the value of Picture Alt DbrHEnable Flag is 1, the value of Picture AltDbrEnableFlag is 1, otherwise, the value of PictureAltDbrEnableFlag is 0.

[000326] The following method can be used to obtain dbr_th, dbr_offset0, dbr_offset1, alt_dbr_offset0 and alt_dbr_offset1:

[000327] For the vertical border dbr_th=DbrVThreshold, dbr_offset0=DbrVOffset0, dbr_offset1=DbrVGffset1, alt_dbr_offset0=DbrVAltOffset0 and alt_dbr_offset1=DbrVAltOffset1.

[000328] For the horizontal border dbr_th=DbrHTreshold, dbr_offset0=DbrHOffset0, dbr_offset1=DbrHOffset1, alt_dbr_offset0=DbrHAltOffset0 and alt_dbr _offset1=DbrHAltOffset1.

[000329] (1) The boundary filtering process when the BS value of the luminance component is 4 is as follows (using the advanced filtering mode for processing):

[000330] When the value of BS is 4, the filtering calculation processes for p0, p1, p2 and q0, q1, q2 are as follows:

[000331] P0=(p2 * 3 + p1 * 8 + p0 * 10 + q0 * 8 + q1 * 3 + 16) >> 5;

[000332] P1=(p2 * 4 + p1 * 5 + p0 * 4 + q0 * 3 + 8) >> 4;

[000333] P2=(p3 * 2 + p2 * 2 + p1 * 2 + p0 * 1 + q0 * 1 + 4) >> 3;

[000334] Q0=(p1 * 3 + p0 * 8 + q0 * 10 + q1 * 8 + q2 x 3 + 16)>> 5;

[000335] Q1=(p0 * 3 + q0 * 4 + q1 * 5 + q2 * 4 + 8) >> 4;

[000336] Q2=(р0 * 1 + q0 * 1 + q1 * 2 + q2 * 2 + q3 * 2 + 4) >> 3.

[000337] P0, P1, P2 and Q0, Q1, Q2 filtered values (filtered pixel values).

[000338] After receiving P0, P1, P2 and Q0, Q1, Q2, if the value of PhDbrEnableFlag is 1, then,

[000339] if pi>Pi + dbr_th, then Pi'=clip((Pi + pi + 1)>> 1 + dbr_offset0); otherwise, if pi<Pi dbr_th, then Pi-clip((Pi + pi + 1)>> 1 + dbr_offset1), where i=0, 1 or 2;

[000340] if qi>Qi + dbr_th, then Qi'=clip((Qi + qi + 1)>> 1 + dbr_offset0); otherwise, if qi<Qi-dbr_th, then Qi'=clip((Qi + qi + 1)>> 1 + dbr_offset1), where i=0, 1 or 2.

[000341] In the above formulas, pi may represent an original pixel value, qi may represent an original pixel value, Pi may represent a filtered pixel value, Qi may represent a filtered pixel value, Pi' may represent a refined pixel value, and Qi' may represent a refined pixel value.

[000342] (2) The boundary filtering process when the BS value of the luminance component (using the advanced filtering mode for processing) is 3 is as follows:

[000343] When the value of BS is 3, the filtering calculation processes for p0, p1 and q0, q1 are as follows:

[000344] P0=(p2 + (p1 << 2) + (p0 << 2) + (p0 << 1) + (q0 << 2) + q1 + 8) >> 4;

[000345] P1=((p2 << 1) + p2 + (p1 << 3) + (p0 << 2) + q0 + 8) >> 4;

[000346] Q0=(p1 + (p0 << 2) + (qO << 2) + (qO << 1) + (q1 << 2) + q2 + 8) >> 4;

[000347] Q1=((q2 << 1) + q2 + (q1 << 3) + (qO << 2) + pO + 8) >> 4.

[000348] P0, P1 and Q0, Q1 are filtered values (filtered pixel values).

[000349] After receiving P0, P1 and Q0, Q1, if the value of PhDbrEnableFlag is 1, then,

[000350] if pi>Pi + dbr_th, then Pi'=clip((Pi + pi + 1)>> 1 + dbr_offset0); otherwise, if pi<Pi -dbr_th, then Pi -clip((Pi + pi + 1)>> 1 + dbr_offset1), where i=0, 1;

[000351] if qi>Qi + dbr_th, then Qi'=clip((Qi + qi + 1)>> 1 + dbr_offset0); otherwise, if qi<Qi-dbr_th, then Qi'=clip((Qi + qi + 1)>> 1 + dbr_offset1), where i=0, 1.

[000352] In the above formulas, pi may represent the original pixel value, qi may represent the original pixel value, Pi may represent the filtered pixel value, Qi may represent the filtered pixel value, Pi' may represent the refined pixel value, and Qi' may represent the refined pixel value.

[000353] (3) The boundary filtering process when the BS value of the luminance component is 2 (using the advanced filtering mode for processing) is as follows:

[000354] When the value of BS is 2, the filtering calculation processes for p0 and q0 are as follows:

[000355] P0=((p1 << 1) + p1 + (p0 << 3) + (p0 << 1) + (q0 << 1) + q0 + 8) >> 4;

[000356] Q0=((р0 << 1) + р0 + (q0 << 3) + (q0 << 1) + (q1 << 1) + q1 + 8) >> 4.

[000357] P0 and Q0 are both filtered values (filtered pixel values).

[000358] After receiving P0 and Q0, if the PhDbrEnableFlag value is 1, then:

[000359] if pi>Pi + dbr_th, then Pi'=clip((Pi + pi + 1)>> 1 + dbr_offset0); otherwise, if pi<Pi -dbr_th, then Pi' =clip((Pi + pi + 1)>> 1 + dbr_offset1), where i=0;

[000360] if qi>Qi + dbr_th, then Qi'=clip((Qi + qi + 1)>> 1 + dbr_offset0); otherwise, if qi<Qi-dbr_th, then Qi'=clip((Qi + qi + 1)>> 1 + dbr_offset1), where i=0.

[000361] In the above formulas, pi may represent the original pixel value, qi may represent the original pixel value, Pi may represent the filtered pixel value, Qi may represent the filtered pixel value, Pi' may represent the refined pixel value, and Qi' may represent the refined pixel value.

[000362] (4) The boundary filtering process when the BS value of the luminance component is 1 (using the advanced filtering mode for processing) is as follows:

[000363] When the value of BS is 1, the filtering calculation processes for p0 and q0 are as follows:

[000364] Р0=((р0 << 1) + р0 + q0 + 2) >> 2;

[000365] Q0=((q0 << 1) + q0 + p0 + 2) >> 2.

[000366] P0 and Q0 are filtered values (filtered pixel values).

[000367] After receiving P0 and Q0, if the value of PhDbrEnableFla is 1, then:

[000368] if pi>Pi + dbr_th, then Pi'=clip((Pi + pi + 1)>> 1 + dbr_offset0); otherwise, if pi<Pi -dbr_th, then Pi'=clip((Pi + pi + 1)>> 1 + dbr_offset1), where i=0;

[000369] if qi>Qi + dbr_th, then Qi'=clip((Qi + qi + 1)>> 1 + dbr_offset0); otherwise, if qi<Qi-dbr_th, then Qi'=clip((Qi + qi + 1)>> 1 + dbr_offset1), where i=0.

[000370] In the above formulas, pi may represent the original pixel value, qi may represent the original pixel value, Pi may represent the filtered pixel value, Qi may represent the filtered pixel value, Pi' may represent the refined pixel value, and Qi' may represent the refined pixel value.

[000371] (5) The boundary filtering process when the BS value of the luminance component is 0 is performed by method 1 (using the advanced refinement mode for processing):

[000372] When the value of BS is 0, the filtering calculation processes for pi and qi are as follows:

[000373] The gradient value DPi for pi and the gradient value DQi for qi are determined. For example, DPi=(pi-qi + 2) >> 2 and DQi=(qi-pi + 2) >> 2, or DPi=(pi-qi + 1) >> 1 and DQi=(qi-pi + 1) >> 1.

[000374] After receiving DPi and DQi, if the PhAltDbrEnableFlag value is 1, then:

[000375] if DPi>dbr_th, then Pi=clip(pi + alt_dbr_offset0); otherwise, if DPi<dbr_th, then Pi=clip(pi + alt_dbr_offset1);

[000376] if DQi>dbr_th, then Qi=clip(qi + alt_dbr_offset0); otherwise, if DQi<-dbr_th, then Qi=clip(qi + alt_dbr_offset1).

[000377] In the above formulas, i may be equal to 0 or may be equal to 0, 1, 2, etc., which is not limited here.

[000378] In the above formulas, pi may represent the original pixel value, qi may represent the original pixel value, DPi may represent the gradient value, DQi may represent the gradient value, Pi may represent the refined pixel value, and Qi may represent the refined pixel value.

[000379] (6) The boundary filtering process when the BS value of the luminance component is 0 is performed by method 2 (using the advanced refinement mode for processing):

[000380] When the value of BS is 0, the filtering calculation processes for pi and qi are as follows:

[000381] Determine the gradient value DPi for pi and the gradient value DQi for qi. For example, DPi=(pi-qi + 1) >> 1 and DQi=(qi-pi + 1) >> 1.

[000382] After receiving DPi and DQi, if the PhAltDbrEnableFlag value is 1, then:

[000383] if DPi>2*dbr_th, then Pi=clip(pi + alt_dbr_offset0); otherwise, if DPi<-2*dbr_th, then Pi=clip(pi + alt_dbr_offset1);

[000384] if DQi>2*dbr_th, then Qi=clip(qi + alt_dbr_offset0); otherwise, if DQi<-2*dbr_th, then Qi=clip(qi + alt_dbr_offset1).

[000385] In the above formulas, 2*dbr_th and 2*dbr_th may be refinement threshold values in the above-described embodiments of the invention.

[000386] In the above formulas, i may be equal to 0 or may be equal to 0, 1, 2, etc., which is not limited here.

[000387] In the above formulas, pi may represent the original pixel value, qi may represent the original pixel value, DPi may represent the gradient value, DQi may represent the gradient value, Pi may represent the refined pixel value, and Qi may represent the refined pixel value.

[000388] (7) The boundary filtering process when the BS value of the luminance component is 0 is performed by method 3 (using the advanced refinement mode for processing):

[000389] When the value of BS is 0, the filtering calculation processes for pi and qi are as follows:

[000390] The gradient value DPi for pi and the gradient value DQi for qi are determined. For example, the gradient value DPi and the gradient value DQi may be determined as follows: DPi=((pi << 1) + pi + qi + 2) >> 2 and DQi=((qi << 1) + qi + pi + 2) >> 2.

[000391] After receiving DPi and DQi, if the PhAltDbrEnableFlag value is 1, then:

[000392] if pi>DPi + dbr_th, then Pi=clip(pi + alt_dbr_offset0); otherwise, if pi<DPi-dbr_th, then Pi=clip(pi + alt_dbr_offset1 );

[000393] if qi>DQi + dbr_th, then Qi=clip(qi + alt_dbr_offset0); otherwise, if qi<DQi-dbr_th, then Qi=clip(qi + alt_dbr_offset1 ).

[000394] In one possible implementation, the above expression may be equivalent to the following form of expression:

[000395] The gradient value DPi for pi and the gradient value DQi for qi are determined. For example, the gradient value DPi and the gradient value DQi can be determined as follows: DPi=pi - (((pi << 1) + pi + qi + 2) >> 2) and DQi=qi- (((qi << 1) + qi + pi + 2) >> 2).

[000396] After receiving DPi and DQi, if the PhAltDbrEnableFlag value is 1, then:

[000397] if DPi>dbr_th, then Pi=clip(pi + alt_dbr_offset0); otherwise, if DPi<dbr_th, then Pi=clip(pi + alt dbr offset1);

[000398] if DQi>dbr_th, then Qi=clip(qi + alt_dbr_offset0); otherwise, if DQi<-dbr_th, then Qi=clip(qi + alt_dbr_offset1).

[000399] In the above formulas, i may be equal to 0 or may be equal to 0, 1, 2, etc., which is not limited here.

[000400] In the above formulas, pi may represent the original pixel value, qi may represent the original pixel value, DPi may represent the gradient value, DQi may represent the gradient value, Pi may represent the refined pixel value, and Qi may represent the refined pixel value.

[000401] In the above embodiment of the invention, clip(x) represents that x is limited to [0, 2^(bit_depth)-1] (the interval includes 0 and 2^(bit_depth)-1), where bit_depth represents the bit depth of the image, which is typically 8, 10, 12, or the like.

[000402] (8) The boundary filtering process when the BS value of the luminance component is 0 is performed by method 4 (using the advanced refinement mode for processing):

[000403] When the value of BS is 0, the filtering calculation processes for pi and qi are as follows:

[000404] The gradient value DPi for pi and the gradient value DQi for qi are determined. For example, the gradient value DPi and the gradient value DQi may be determined as follows: DPi=(qi - pi + 2) >> 2 and DQi=(pi - qi + 2) >> 2.

[000405] After receiving DPi and DQi, if the PhAltDbrEnableFlag value is 1, then:

[000406] if DPi<dbr_th, then Pi=clip(pi + dbr_alt_offset0); otherwise, if DPi>-dbr_th, then Pi=clip(pi + dbr_alt_offset1);

[000407] if DQi<dbr_th, then Qi=clip(qi + alt_dbr_offset0); otherwise, if DQi>dbr_th, then Qi=clip(qi + dbr_alt_offset1).

[000408] In the above formulas, i may be equal to 0 or may be equal to 0, 1, 2, etc., which is not limited here.

[000409] In the above formulas, pi may represent the original pixel value, qi may represent the original pixel value, DPi may represent the gradient value, DQi may represent the gradient value, Pi may represent the refined pixel value, and Qi may represent the refined pixel value.

[000410] (9) The boundary filtering process when the BS value of the luminance component is 0 is performed by method 5 (using the advanced refinement mode for processing):

[000411] When the value of BS is 0, the filtering calculation processes for pi and qi are as follows:

[000412] The gradient value DPi for pi and the gradient value DQi for qi are determined. For example, the gradient value DPi and the gradient value DQi can be determined as follows: DPi=pi - (((pi << 1) + pi + qi + 2) >> 2), i.e. DPi=(pi - qi -2) >> 2, and DQi=qi - (((qi << 1) + qi + pi + 2) >> 2), i.e. DQi=(qi - pi - 2) >> 2.

[000413] After receiving DPi and DQi, if the PhAltDbrEnableFlag value is 1, then:

[000414] if DPi>dbr_th, then Pi=clip (pi + dbr_alt_offset0); otherwise, if DPi<- dbr_th, then Pi=clip (pi + dbr_alt_offset1);

[000415] if DQi>dbr_th, then Qi=clip(qi + dbr_alt_offset0); otherwise, if DQi<-dbr_th, then Qi=clip(qi + dbr_alt_offset1).

[000416] In the above formulas, i may be equal to 0 or may be equal to 0, 1, 2, etc., which is not limited here.

[000417] In the above formulas, pi may represent the original pixel value, qi may represent the original pixel value, DPi may represent the gradient value, DQi may represent the gradient value, Pi may represent the refined pixel value, and Qi may represent the refined pixel value.

[000418] Embodiment 17 of the invention: for embodiments 11 and 12 of the invention, the high-level syntax of the SPS may be replaced by the high-level syntax of the PPS, or the high-level syntax of the image header, or the high-level syntax of the image, or the high-level syntax of the slice header, or the high-level syntax of the CTU, or the high-level syntax of the CU, and the types of high-level syntaxes are not limited here, provided that the high-level syntaxes can transmit dbr_enable_flag or adbr_enable_flag. For embodiments 13 and 14 of the invention, the high-level syntax of the image header can be replaced by a high-level syntax of the SPS, or a high-level syntax of the PPS, or a high-level syntax of the image, or a high-level syntax of the slice header, or a high-level syntax of the CTU, or a high-level syntax of the CU, and the types of high-level syntaxes are not limited here, if the high-level syntaxes can convey the contents of table 1 and table 2, namely, the high-level syntaxes can convey an extended refinement mode enable flag, an extended filter mode enable flag, a first refinement threshold value, a first filtering threshold value, a first filtering offset value, a second filtering offset value, a first refinement offset value, a second refinement offset value, and the like, wherein the specific implementation is similar to the implementation of embodiments 13 and 14 of the invention and is not repeated here.

[000419] For embodiments 13 and 14 of the invention, the high-level syntax of the image header may be replaced by a high-level syntax of the CTU that conveys parameters related to the DBR, wherein the parameters related to the DBR include a first refinement threshold value, a first filtering threshold value, a first filtering offset value, a second filtering offset value, a first refinement offset value, a second refinement offset value, and the like, as shown in embodiments 13 and 14 of the invention. Alternatively, the high-level syntax of the image header may be replaced by a high-level syntax of the CU that conveys parameters related to the DBR, wherein the parameters related to the DBR include a first refinement threshold value, a first filtering threshold value, a first filtering offset value, a second filtering offset value, a first refinement offset value, a second refinement offset value, and the like, as shown in embodiments 13 and 14 of the invention.

[000420] Embodiment 18: For embodiment 16, this is a deblocking filtering process for the luminance component; further, the luminance component may be replaced by a chrominance component, and the deblocking filtering process is performed for the chrominance component (i.e., the current block is a chrominance component). The deblocking filtering process for the chrominance component is similar to the deblocking filtering process for the luminance component as shown in embodiment 16, and redundant descriptions are not given here.

[000421] In some embodiments of the invention, the above-described embodiments 1 to 18 may be implemented separately or in combinations, for example, embodiment 1 and embodiment 2 may be combined, embodiment 1 and embodiment 3 may be combined, embodiment 1 and embodiment 4 may be combined, embodiment 1 and embodiment 5 may be combined, and embodiment 1 and at least one of embodiments 8 to 18 may be combined; at least two embodiments 8 to 18 may be arbitrarily combined; embodiment 2 and at least one of embodiments 8 to 18 may be combined; embodiment 3 and at least one of embodiments 8 to 18 may be combined; embodiment 4 and at least one of embodiments 8 to 18 may be combined; embodiment 5 of the invention and at least one of embodiments 8 to 18 may be combined; embodiment 6 of the invention and at least one of embodiments 8 to 18 may be combined; embodiment 7 of the invention and at least one of embodiments 8 to 18 may be combined. Of course, the above are only a few examples of combination, and at least any two embodiments of the invention from embodiments 1 to 18 may be combined to implement the corresponding process.

[000422] In some embodiments of the invention, the description of the encoder in each of the embodiments of the invention described above may be applied to a decoder, and the decoder may perform the processing in the same way. The description of the decoder may be applied to the encoder, and the encoder may perform the processing in the same way.

[000423] Embodiment 19 of the invention: Based on the same idea of the application as the method described above, an embodiment of the present disclosure provides a decoding device that is applied to a decoder. The decoding device comprises: a memory configured to store video data; a decoder configured to implement the encoding and decoding method shown in embodiments 1 to 18 of the invention, namely, to implement a processing flow of the decoder.

[000424] For example, in one possible implementation, the decoder is configured to perform the following:

[000425] if the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, determining a gradient value of the current pixel point based on the original pixel value of the current pixel point and the original pixel value of the surrounding pixel point of the current pixel point; based on the gradient value of the current pixel point and the original pixel value of the current pixel point, determining a refined pixel value of the current pixel point.

[000426] Based on the same application concept as the above-described method, an embodiment of the present disclosure provides an encoding device that is applied to an encoder. The encoding device comprises: a memory configured to store video data; an encoder configured to implement the encoding and decoding method shown in embodiments 1 to 18 of the invention, namely, to implement a processing flow of the encoder.

[000427] For example, in one possible implementation, the encoder is configured to perform the following:

[000428] if the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, determining a gradient value of the current pixel point based on the original pixel value of the current pixel point and the original pixel value of the surrounding pixel point of the current pixel point; based on the gradient value of the current pixel point and the original pixel value of the current pixel point, determining a refined pixel value of the current pixel point.

[000429] Based on the same application concept as the above-described method, an embodiment of the present disclosure provides a decoder device (also called a video decoder). From the hardware level perspective, reference may be made to Fig. 5A illustrating a hardware architecture diagram of the decoder device, which comprises: a processor 511 and a computer-readable storage medium 512. The computer-readable storage medium 512 stores computer-readable instructions executable by the processor 511, and the processor 511 is configured to execute the computer-readable instructions for implementing the method of the above embodiments 1 to 18. For example, the processor 511 is configured to execute the computer-readable instructions for performing the following steps:

[000430] if the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, determining a gradient value of the current pixel point based on an original pixel value of the current pixel point and an original pixel value of a surrounding pixel point of the current pixel point; based on the gradient value of the current pixel point and the original pixel value of the current pixel point, determining a refined pixel value of the current pixel point.

[000431] Based on the same application concept as the above-described method, an embodiment of the present disclosure provides an encoder device (also called a video encoder). From the hardware level perspective, reference can be made to Fig. 5B illustrating a hardware architecture diagram of the encoder device, which comprises: a processor 521 and a computer-readable storage medium 522. The computer-readable storage medium 522 stores computer-readable instructions executable by the processor 521, and the processor 521 is configured to execute the computer-readable instructions for implementing the method of the above embodiments 1 to 18. For example, the processor 521 is configured to execute the computer-readable instructions for performing the following steps:

[000432] if the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, determining a gradient value of the current pixel point based on an original pixel value of the current pixel point and an original pixel value of a surrounding pixel point of the current pixel point; based on the gradient value of the current pixel point and the original pixel value of the current pixel point, determining a refined pixel value of the current pixel point.

[000433] Based on the same application concept as the above-described method, an embodiment of the present disclosure provides a computer-readable storage medium on which computer instructions are stored. The computer instructions are executed by a processor to implement the method disclosed in the above-described embodiments of the present invention, for example, the encoding and decoding method mentioned in the above-described embodiments of the invention. The computer-readable storage medium may be any electronic, magnetic, optical or physical storage device and may contain or store information such as executable instructions, data and the like. For example, the computer-readable storage medium may be random access memory (RAM), volatile memory, non-volatile memory, flash memory, a storage device (such as a hard disk), a solid-state hard disk, any type of storage disk (such as a compact disc, a digital video disc (DVD)) or a similar storage medium, or a combination thereof.

[000434] Based on the same application concept as the above-described method, an embodiment of the present disclosure provides a computer application program that is executed by a processor to implement the encoding and decoding method as disclosed in the above-described embodiments of the invention.

[000435] Based on the same application concept as the above-described method, an embodiment of the present disclosure provides an encoding and decoding device that is applied to an encoder or a decoder. The encoding and decoding device comprises:

[000436] a determining module configured to, if a current pixel point in a current block satisfies a condition for enabling the extended refinement mode, determine a gradient value of the current pixel point based on an original pixel value of the current pixel point and an original pixel value of a surrounding pixel point of the current pixel point; and a processing module configured to determine, based on the gradient value of the current pixel point and the original pixel value of the current pixel point, a refined pixel value of the current pixel point.

[000437] In some embodiments of the invention, the processing module, when determining the refined pixel value of the current pixel point based on the gradient value of the current pixel point and the original pixel value of the current pixel point, is configured to perform the following:

[000438] based on a gradient value of the current pixel point, an original pixel value of the current pixel point, a first refinement threshold value, a second refinement threshold value, a first refinement offset value, and a second refinement offset value, determining a refined pixel value of the current pixel point.

[000439] In some embodiments of the invention, a processing module configured, based on a gradient value of a current pixel point, an original pixel value of the current pixel point, a first refinement threshold value, a second refinement threshold value, a first refinement offset value, and a second refinement offset value, to determine a refined pixel value of the current pixel point, is configured to: if the gradient value of the current pixel point is greater than the first refinement threshold value, determine the refined pixel value of the current pixel point based on the original pixel value of the current pixel point and the first refinement offset value;

[000440] if the gradient value of the current pixel point is less than the second refinement threshold value, determine a refined pixel value of the current pixel point based on the original pixel value of the current pixel point and the second refinement offset value.

[000441] In one possible implementation, if the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, the determining module is also configured to determine a reference pixel point corresponding to the current pixel point from a neighboring block of the current block and, based on an original pixel value of the reference pixel point and an original pixel value of a surrounding pixel point of the reference pixel point, determine a gradient value of the reference pixel point; the processing module is also configured to determine a refined pixel value of the reference pixel point based on the gradient value of the reference pixel point and the original pixel value of the reference pixel point.

[000442] In some embodiments of the invention, the processing module, when determining the refined pixel value of the pixel reference point based on the gradient value of the pixel reference point and the original pixel value of the pixel reference point, is configured to perform the following:

[000443] based on the gradient value of the pixel reference point, the original pixel value of the pixel reference point, the third refinement threshold value, the fourth refinement threshold value, the third refinement offset value, and the fourth refinement offset value, determining a refined pixel value of the pixel reference point.

[000444] In some embodiments of the invention, a processing module configured, based on a gradient value of a reference point of a pixel, an original pixel value of the reference point of the pixel, a third refinement threshold value, a fourth refinement threshold value, a third refinement offset value, and a fourth refinement offset value, to determine a refined pixel value of the reference point of the pixel, is configured to: if the gradient value of the reference point of the pixel is greater than the third refinement threshold value, determine the refined pixel value of the reference point of the pixel based on the original pixel value of the reference point of the pixel and the third refinement offset value;

[000445] if the gradient value of the pixel anchor point is less than a fourth refinement threshold value, determine a refined pixel value of the pixel anchor point based on the original pixel value of the pixel anchor point and the fourth refinement offset value.

[000446] In one possible implementation, a determining module, when determining that a current pixel point in a current block satisfies a condition for enabling an extended refinement mode, is configured to perform the following: if the strength of a boundary of a boundary to be filtered corresponding to the current pixel point in the current block satisfies the condition for enabling an extended refinement mode, determining that the current pixel point satisfies the condition for enabling an extended refinement mode; or, if property information corresponding to the current block satisfies the condition for enabling an extended refinement mode, determining that the current pixel point in the current block satisfies the condition for enabling an extended refinement mode.

[000447] In some embodiments of the invention, the processing module is also configured to: if the current pixel point in the current block satisfies the condition for enabling the general filtering mode, perform deblocking filtering of the original pixel value of the current pixel point to obtain a filtered pixel value of the current pixel point; if the current pixel point in the current block satisfies the condition for enabling the extended filtering mode, determine a refined pixel value of the current pixel point based on the filtered pixel value of the current pixel point and the original pixel value of the current pixel point.

[000448] In some embodiments of the invention, the processing module, when determining the refined pixel value of the current pixel point based on the filtered pixel value of the current pixel point and the original pixel value of the current pixel point, is configured to perform the following: based on the filtered pixel value of the current pixel point, the original pixel value of the current pixel point, a first filtering threshold value, a second filtering threshold value, a first filtering offset value, and a second filtering offset value, determining the refined pixel value of the current pixel point, wherein the first filtering threshold value and the second filtering threshold value are numbers that are opposite to each other.

[000449] In some embodiments of the invention, if the current pixel point in the current block satisfies the condition for enabling the common filtering mode, the processing module is also configured to determine a reference pixel point corresponding to the current pixel point from a neighboring block of the current block and perform deblocking filtering on the original pixel value of the reference pixel point to obtain a filtered pixel value of the reference pixel point;

[000450] if the current pixel point in the current block satisfies the condition for enabling the advanced filtering mode, determining a refined pixel value of the pixel reference point based on the filtered pixel value of the pixel reference point and the original pixel value of the pixel reference point.

[000451] In some embodiments of the invention, the processing module, when determining the refined pixel value of the pixel reference point based on the filtered pixel value of the pixel reference point and the original pixel value of the pixel reference point, is configured to perform the following: based on the filtered pixel value of the pixel reference point, the original pixel value of the pixel reference point, a third filtering threshold value, a fourth filtering threshold value, a third filtering offset value, and a fourth filtering offset value, determining the refined pixel value of the pixel reference point, wherein the third filtering threshold value and the fourth filtering threshold value are numbers that are opposite to each other.

[000452] The systems, devices, modules or units described in the above embodiments of the invention may be implemented as computer chips or objects or as products with certain functions. A typical implementation device is a computer, and the computer, in a specific form, may be a personal computer, a portable computer, a cellular phone, a camera phone, a smartphone, a personal digital assistant, a media player, a navigation equipment, an e-mail transceiver, a game console, a tablet computer, a wearable device or combinations of any several of these devices. For convenience of description, the above device is divided into various blocks by function during the description. Of course, when implementing the present disclosure, the functions of each block may be implemented in one or more software and/or hardware.

[000453] It will be understood by those skilled in the art that embodiments of the present invention may be provided in the form of methods, systems, or computer program products. Accordingly, the present disclosure may take the form of a purely hardware embodiment of the invention, a purely software embodiment of the invention, or an embodiment of the invention combining software and hardware. Furthermore, embodiments of the present disclosure may take the form of a computer program product implemented on one or more computer-accessible storage media (including, but not limited to, disk storage devices, CD-ROMs, optical storage devices, etc.) containing computer-accessible program codes.

[000454] The present description is presented with reference to block diagrams and/or structure diagrams of methods, devices (systems) and computer program products disclosed in embodiments of the present disclosure. It should be understood that each flow and/or block in the block diagrams and/or structure diagrams and combinations of flows and/or blocks in the block diagrams and/or structure diagrams can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor or other programmable data processing equipment to create a machine, so that the instructions executed by the processor or other programmable data processing device provide the device for implementing the functions indicated in one or more flows in the block diagram and/or in one or more blocks in the structure diagram.

[000455] These computer program instructions can also be stored in a computer-readable memory capable of controlling a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory create an industrial product, including a device for executing instructions, where the device for executing instructions implements the functions indicated in one or more flows in the flow chart and/or in one or more blocks in the structural diagram. These computer program instructions can also be loaded into a computer or other programmable data processing device, so that a series of operational steps can be executed on a computer or other programmable device to create a computer-implemented processing, and thus the instructions executed on the computer or other programmable device provide steps for implementing the function indicated in one or more flows in the flow chart and/or in one or more blocks in the structural diagram. The above are only some examples of the present disclosure, which do not limit the present invention. For those skilled in the art, the present disclosure can have various changes and modifications. Any modifications, equivalent replacements, improvements, etc., made within the scope of the invention are within the scope of the claims.

Claims (71)

1. A decoding method comprising: in response to determining that a current pixel point in the current block satisfies a condition for enabling the extended refinement mode, determining a gradient value of the current pixel point based on an original pixel value of the current pixel point and an original pixel value of a surrounding pixel point of the current pixel point; based on the gradient value of the current pixel point and the original pixel value of the current pixel point, determining a refined pixel value of the current pixel point; wherein determining that the current pixel point in the current block satisfies the condition for enabling the extended refinement mode includes: in response to determining that the strength of the boundary of the boundary to be filtered corresponding to the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, determining that the current pixel point satisfies the condition for enabling the extended refinement mode; wherein determining the refined pixel value of the current pixel point based on the gradient value of the current pixel point and the original pixel value of the current pixel point includes: based on a gradient value of the current pixel point, an original pixel value of the current pixel point, a first refinement threshold value, a second refinement threshold value, a first refinement offset value, and a second refinement offset value, determining a refined pixel value of the current pixel point; wherein in response to determining that the gradient value of the current pixel point is greater than the first refinement threshold value, a refined pixel value of the current pixel point is determined based on the original pixel value of the current pixel point and the first refinement offset value; in response to determining that the gradient value of the current pixel point is less than the second refinement threshold value, determining a refined pixel value of the current pixel point based on the original pixel value of the current pixel point and the second refinement offset value; where the pixel value of the current pixel point in the current block is either the luminance component or the chrominance component. 2. The method according to claim 1, wherein determining that the strength of the boundary of the boundary to be filtered, corresponding to the current pixel point in the current block, satisfies the condition for turning on the extended refinement mode, includes: in response to determining that the boundary strength of the boundary to be filtered corresponding to the current pixel point is a predetermined first value, determining that the boundary strength of the boundary to be filtered satisfies a condition for turning on the extended refinement mode; wherein the predetermined first value is 0. 3. The method according to item 1, wherein, in response to determining that the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, the method also includes: determining a pixel reference point corresponding to the current pixel point from an adjacent block of the current block and, based on an initial pixel value of the pixel reference point and an initial pixel value of a surrounding pixel point of the pixel reference point, determining a gradient value of the pixel reference point; based on the value of the gradient of the pixel reference point, the original pixel value of the pixel reference point, the third refinement threshold value, the fourth refinement threshold value, the third refinement offset value and the fourth refinement offset value, determining the refined pixel value of the pixel reference point; wherein in response to determining that the value of the gradient of the pixel reference point is greater than the third refinement threshold value, the refined pixel value of the pixel reference point is determined based on the original pixel value of the pixel reference point and the third refinement offset value; in response to determining that the value of the gradient of the pixel reference point is less than the fourth refinement threshold value, the refined pixel value of the pixel reference point is determined based on the original pixel value of the pixel reference point and the fourth refinement offset value. 4. The method according to any of paragraphs 1-3, also including: determining a first refinement threshold value, a first refinement offset value, a second refinement offset value, a third refinement threshold value, a third refinement offset value, and a fourth refinement offset value corresponding to the current block from the high-level syntax; wherein, before determining that the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, the method also includes: in response to determining that an extended refinement mode enable flag corresponding to the current block allows the current block to enable the extended refinement mode, determining whether a current pixel point in the current block satisfies a condition for enabling the extended refinement mode; wherein the method also includes: determining the flag for enabling the extended refinement mode corresponding to the current block from the high-level syntax. 5. The method according to paragraph 1, also including: in response to determining that the current pixel point satisfies the general filtering mode enabling condition, performing deblocking filtering on the original pixel value of the current pixel point to obtain a filtered pixel value of the current pixel point; and in response to determining that the current pixel point satisfies the condition for enabling the advanced filtering mode, determining a refined pixel value of the current pixel point based on the filtered pixel value of the current pixel point and the original pixel value of the current pixel point; and/or wherein determining the refined pixel value of the current pixel point based on the filtered pixel value of the current pixel point and the original pixel value of the current pixel point includes: based on the filtered pixel value of the current pixel point, the original pixel value of the current pixel point, the first filtering threshold value, the second filtering threshold value, the first filtering offset value and the second filtering offset value, determining a refined pixel value of the current pixel point; wherein the first filtering threshold value and the second filtering threshold value are numbers that are opposite to each other; and/or the method also includes: in response to determining that the extended filtering mode enable flag corresponding to the current block enables the current block to enable the extended filtering mode, determining whether the current pixel point satisfies the extended filtering mode enable condition. 6. The method according to claim 5, further comprising, in response to determining that the current pixel point satisfies the condition for enabling the general filtering mode: determining the pixel reference point corresponding to the current pixel point from the neighboring block of the current block and performing deblocking filtering on the original pixel value of the pixel anchor point to obtain a filtered pixel value of the pixel anchor point; wherein in response to determining that the current pixel point satisfies the condition for enabling the extended filtering mode, the method also includes: determining a refined pixel value of the pixel anchor point based on the filtered pixel value of the pixel anchor point and the original pixel value of the pixel anchor point. 7. The method according to claim 6, wherein determining the refined pixel value of the pixel reference point based on the filtered pixel value of the pixel reference point and the original pixel value of the pixel reference point comprises: based on the filtered pixel value of the pixel reference point, the original pixel value of the pixel reference point, the third filtering threshold value, the fourth filtering threshold value, the third filtering offset value and the fourth filtering offset value, determining a refined pixel value of the pixel reference point, wherein the third filtering threshold value and the fourth filtering threshold value are numbers that are opposite to each other; wherein the first filtering threshold value, the first filtering offset value, the second filtering offset value, the third filtering threshold value, the third filtering offset value and the fourth filtering offset value corresponding to the current block are determined from the high-level syntax. 8. The method according to claim 5, wherein determining that the current pixel point in the current block satisfies the condition for enabling the extended filtering mode includes: in response to determining that the strength of the boundary of the boundary to be filtered corresponding to the current pixel point in the current block satisfies the condition for enabling the advanced filtering mode and the absolute value of the difference between the filtered pixel value of the current pixel point and the original pixel value of the current pixel point exceeds a predetermined threshold value, determining that the current pixel point satisfies the condition for enabling the advanced filtering mode. 9. The method according to claim 8, wherein determining that the strength of the boundary of the boundary to be filtered, corresponding to the current pixel point, satisfies the condition for enabling the extended filtering mode, includes: in response to determining that the edge strength of the boundary to be filtered corresponding to the current pixel point is a predetermined second value, determining that the edge strength of the boundary to be filtered satisfies a condition for enabling the advanced filtering mode. 10. A coding method comprising: in response to determining that a current pixel point in the current block satisfies a condition for enabling the extended refinement mode, determining a gradient value of the current pixel point based on an original pixel value of the current pixel point and an original pixel value of a surrounding pixel point of the current pixel point; based on the gradient value of the current pixel point and the original pixel value of the current pixel point, determining a refined pixel value of the current pixel point; wherein determining that the current pixel point in the current block satisfies the condition for enabling the extended refinement mode includes: in response to determining that the strength of the boundary of the boundary to be filtered corresponding to the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, determining that the current pixel point satisfies the condition for enabling the extended refinement mode; wherein determining the refined pixel value of the current pixel point based on the gradient value of the current pixel point and the original pixel value of the current pixel point includes: based on a gradient value of the current pixel point, an original pixel value of the current pixel point, a first refinement threshold value, a second refinement threshold value, a first refinement offset value, and a second refinement offset value, determining a refined pixel value of the current pixel point; wherein in response to determining that the gradient value of the current pixel point is greater than the first refinement threshold value, a refined pixel value of the current pixel point is determined based on the original pixel value of the current pixel point and the first refinement offset value; in response to determining that the gradient value of the current pixel point is less than the second refinement threshold value, determining a refined pixel value of the current pixel point based on the original pixel value of the current pixel point and the second refinement offset value, where the pixel value of the current pixel point in the current block is either the luminance component or the chrominance component. 11. A decoding device comprising: a determining module configured to, in response to determining that a current pixel point in a current block satisfies a condition for enabling the extended refinement mode, determine a gradient value of the current pixel point based on an original pixel value of the current pixel point and an original pixel value of a surrounding pixel point of the current pixel point; and a processing module configured to, based on a gradient value of the current pixel point and an original pixel value for the current pixel point, determine a refined pixel value of the current pixel point; wherein determining that the current pixel point in the current block satisfies the condition for enabling the extended refinement mode includes: in response to determining that the strength of the boundary of the boundary to be filtered corresponding to the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, determining that the current pixel point satisfies the condition for enabling the extended refinement mode; wherein determining the refined pixel value of the current pixel point based on the gradient value of the current pixel point and the original pixel value of the current pixel point includes: based on a gradient value of the current pixel point, an original pixel value of the current pixel point, a first refinement threshold value, a second refinement threshold value, a first refinement offset value, and a second refinement offset value, determining a refined pixel value of the current pixel point; wherein in response to determining that the gradient value of the current pixel point is greater than the first refinement threshold value, a refined pixel value of the current pixel point is determined based on the original pixel value of the current pixel point and the first refinement offset value; in response to determining that the gradient value of the current pixel point is less than the second refinement threshold value, determining a refined pixel value of the current pixel point based on the original pixel value of the current pixel point and the second refinement offset value, where the pixel value of the current pixel point in the current block is either the luminance component or the chrominance component. 12. An encoding device comprising: a determining module configured to, in response to determining that a current pixel point in a current block satisfies a condition for enabling the extended refinement mode, determine a gradient value of the current pixel point based on an original pixel value of the current pixel point and an original pixel value of a surrounding pixel point of the current pixel point; and a processing module configured to, based on the gradient value of the current pixel point and the original pixel value of the current pixel point, determine a refined pixel value of the current pixel point; wherein determining that the current pixel point in the current block satisfies the condition for enabling the extended refinement mode includes: in response to determining that the strength of the boundary of the boundary to be filtered corresponding to the current pixel point in the current block satisfies the condition for enabling the extended refinement mode, determining that the current pixel point satisfies the condition for enabling the extended refinement mode; wherein determining the refined pixel value of the current pixel point based on the gradient value of the current pixel point and the original pixel value of the current pixel point includes: based on a gradient value of the current pixel point, an original pixel value of the current pixel point, a first refinement threshold value, a second refinement threshold value, a first refinement offset value, and a second refinement offset value, determining a refined pixel value of the current pixel point; wherein in response to determining that the gradient value of the current pixel point is greater than the first refinement threshold value, a refined pixel value of the current pixel point is determined based on the original pixel value of the current pixel point and the first refinement offset value; in response to determining that the gradient value of the current pixel point is less than the second refinement threshold value, determining a refined pixel value of the current pixel point based on the original pixel value of the current pixel point and the second refinement offset value, where the pixel value of the current pixel point in the current block is either the luminance component or the chrominance component. 13. A decoder device comprising a processor and a machine-readable storage medium, wherein the machine-readable storage medium stores machine-readable instructions executable by the processor; the processor is configured to execute machine-readable instructions for implementing the method according to any one of claims 1-9. 14. An encoder device comprising a processor and a machine-readable storage medium, wherein the machine-readable storage medium stores machine-readable instructions executable by the processor; the processor is configured to execute machine-readable instructions for implementing the method of claim 10. 15. A machine-readable storage medium that stores machine-readable instructions executable by a processor, wherein the processor is configured to execute the machine-readable instructions for implementing the method according to any one of paragraphs 1-9.