KR20150055858A - Method and apparatus for encoding video, method and apparatus for decoding video using differential residual signal - Google Patents

Abstract

A method for encoding and decoding a differential residual signal based on hierarchical information of data units having a hierarchical structure is disclosed. The video coding method divides a picture into a maximum coding unit, generates a residual signal of a prediction unit included in the coding unit based on the coding unit and the prediction unit obtained by hierarchically dividing the maximum coding unit, Unit and a conversion unit, generates control information for generating a differential residual signal of a residual signal included in the encoding unit, and generates control information for generating a residual residual signal of the residual signal included in the encoding unit Thereby generating a differential residual signal.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method and an apparatus for encoding video using differential residual signals, a decoding method and apparatus thereof,

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to encoding and decoding video, and more particularly, to a method of encoding and decoding a residual signal.

A video codec such as H.264 / AVC performs encoding and decoding in units of sub-blocks obtained by dividing or dividing a plurality of macroblocks or macroblocks included in one frame. Then, each macroblock is encoded in all coding modes available in inter prediction and intra prediction, and then the macroblocks are coded using the bit rate required for coding the block and the degree of distortion between the original block and the decoded block Therefore, the optimal encoding mode is set and the block is encoded.

Background of the Invention [0002] As the development and dissemination of hardware capable of playing back and storing high-resolution or high-definition video content increases the need for video codecs to effectively encode or decode high-definition or high-definition video content. According to a conventional video codec, a video is encoded according to a limited encoding method based on a macroblock of a predetermined size.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a method for efficiently encoding and decoding a residual signal in a video codec based on a coding unit of a tree structure having a hierarchical structure.

According to an aspect of the present invention, there is provided a video encoding method including dividing a picture into at least one maximum encoding unit which is a maximum-size encoding unit, Based on a coding unit obtained by hierarchically dividing the maximum coding unit according to a depth indicating the number of spatial division of the maximum coding unit and a prediction unit for prediction of the coding unit, Generating a signal; Generates control information for generating a residual residual signal of a residual signal included in the encoding unit based on at least one layer information among the encoding units, the prediction units, and the conversion units used for conversion of the encoding units step; And generating a differential residual signal of a residual signal included in the coding unit based on the control information.

The video coding apparatus according to an embodiment divides a picture into at least one maximum coding unit which is a coding unit of the maximum size and divides the maximum coding unit hierarchically according to a depth indicating the number of spatial division of the maximum coding unit A prediction coding unit for generating a residual signal of a prediction unit included in the coding unit based on a coding unit and a prediction unit for prediction of the coding unit; Generates control information for generating a residual residual signal of a residual signal included in the encoding unit based on at least one layer information among the encoding units, the prediction units, and the conversion units used for conversion of the encoding units A differential residual control information generation unit; And a differential residual signal generator for generating a differential residual signal of a residual signal included in the coding unit based on the control information.

According to an embodiment of the present invention, there is provided a video decoding method comprising the steps of: extracting, from a bit stream, hierarchical information of a coding unit obtained by dividing a maximum coding unit, which is a coding unit of a maximum size obtained by dividing a picture, Obtaining information of a coding unit, layer information of a conversion unit for inverse transformation of the coding unit, and a differential residual signal of the coding unit; Obtaining control information used for generating the differential residual signal based on hierarchical information of at least one of the encoding unit, the prediction unit, and the conversion unit; And restoring the residual signal of the coding unit from the differential residual signal of the coding unit based on the control information.

According to another embodiment of the present invention, there is provided a video decoding method comprising the steps of: extracting, from a bitstream, hierarchical information of a coding unit obtained by dividing a maximum coding unit, which is a coding unit of a maximum size obtained by dividing a picture, Information of a coding unit, layer information of a conversion unit for inverse conversion of the coding unit, and a difference residual signal of the coding unit; Obtaining control information, which is generated from the bitstream based on at least one layer information among the encoding unit, the prediction unit, and the conversion unit, and used for generating the differential residual signal; And restoring the residual signal of the coding unit from the differential residual signal of the coding unit based on the control information.

A video decoding apparatus according to an embodiment is a decoding apparatus for decoding, from a bitstream, hierarchical information of a coding unit obtained by dividing a maximum coding unit, which is a coding unit of a maximum size obtained by dividing a picture, A receiving unit for acquiring information of a coding unit, layer information of a conversion unit for inverse conversion of the coding unit, and a differential residual signal of the coding unit; A differential residual control information generation unit for generating control information used for generating the differential residual signal based on at least one layer information among the coding unit, the prediction unit and the conversion unit; And a residual restoring unit for restoring the residual signal of the coding unit from the differential residual signal of the coding unit based on the control information.

A video decoding apparatus according to another embodiment is a video decoding apparatus which extracts, from a bitstream, hierarchical information of a coding unit obtained by dividing a maximum coding unit, which is a coding unit of a maximum size obtained by dividing a picture, Information of a coding unit, hierarchical information of a conversion unit for inverse transformation of the coding unit, differential residual signal of the coding unit, and hierarchical information of at least one of the coding unit, the prediction unit and the conversion unit, A reception unit for acquiring control information used for signal generation; And a residual restoring unit for restoring the residual signal of the coding unit from the differential residual signal of the coding unit based on the control information.

According to the embodiments of the present invention, a difference residual signal, which is a difference value between residual signals in a coding unit, is generated based on hierarchical information of a coding unit of a tree structure, so that in a video codec based on a coding unit of a tree structure, The dual signal can be efficiently encoded.

1 shows a block diagram of a video coding apparatus based on a coding unit of a tree structure according to an embodiment of the present invention.
2 shows a block diagram of a video decoding apparatus based on a coding unit of a tree structure according to an embodiment of the present invention.
FIG. 3 illustrates a concept of an encoding unit according to an embodiment of the present invention.
4 is a block diagram of an image encoding unit based on an encoding unit according to an embodiment of the present invention.
5 is a block diagram of an image decoding unit based on an encoding unit according to an embodiment of the present invention.
FIG. 6 illustrates a depth-based encoding unit and a partition according to an exemplary embodiment of the present invention.
FIG. 7 shows a relationship between an encoding unit and a conversion unit according to an embodiment of the present invention.
FIG. 8 illustrates depth-specific encoding information, in accordance with an embodiment of the present invention.
FIG. 9 shows a depth encoding unit according to an embodiment of the present invention.
FIGS. 10, 11 and 12 show the relationship between an encoding unit, a prediction unit, and a conversion unit according to an embodiment of the present invention.
Fig. 13 shows the relationship between the encoding unit, the prediction unit and the conversion unit according to the encoding mode information in Table 1. Fig.
14 is a block diagram showing a configuration of a video encoding apparatus according to an embodiment.
15 is a block diagram showing the configuration of the predictive encoding unit 1410 shown in Fig.
16 is a diagram illustrating a residual signal of an encoding unit according to an embodiment of the present invention.
17 is a diagram illustrating a process of generating a differential residual signal in the horizontal direction according to an embodiment of the present invention.
18 is a diagram illustrating a process of generating a differential residual signal in the vertical direction according to the present invention.
19A is an example of a coding unit 1910 of a tree structure obtained by dividing the maximum coding unit.
FIG. 19B is an example of a prediction unit 1920 for predictive coding of the coding unit 1910 included in the maximum coding unit of FIG. 19A.
FIG. 19C is an example of a change unit 1930 for conversion of the encoding unit 1910 of FIG. 19A.
20A is a diagram illustrating a method of generating a differential residual signal by using a residual signal of a data unit adjacent in the vertical direction.
20B is a diagram illustrating a method of generating a differential residual signal using a residual signal of a data unit adjacent in the horizontal direction.
21 is a flowchart illustrating a video encoding method according to an embodiment.
22 is a block diagram showing a configuration of a video decoding apparatus according to an embodiment.
23 is a block diagram showing a configuration of a video decoding apparatus according to another embodiment.
24 is a flowchart illustrating a video decoding method according to an embodiment.
25 is a flowchart illustrating a video decoding method according to another embodiment.

1 to 13, a video coding technique and a video coding technique based on a coding unit of a tree structure according to an embodiment are disclosed. 14 to 25, a method of encoding and decoding a residual signal based on a coding unit of a tree structure is disclosed. In the various embodiments described below, 'video' may be generically referred to including still video as well as video such as video.

1 shows a block diagram of a video coding apparatus 100 based on a coding unit of a tree structure according to an embodiment of the present invention.

The video coding apparatus 100 with video prediction based on a coding unit according to an exemplary embodiment includes a maximum coding unit division unit 110, a coding unit determination unit 120, and an output unit 130 . For convenience of explanation, the video encoding apparatus 100 with video prediction based on the encoding unit according to the tree structure according to an embodiment is abbreviated as 'video encoding apparatus 100'.

The maximum coding unit division unit 110 may divide a current picture based on a maximum coding unit which is a coding unit of a maximum size for a current picture of an image. If the current picture is larger than the maximum encoding unit, the image data of the current picture may be divided into at least one maximum encoding unit. The maximum encoding unit according to an exemplary embodiment may be a data unit of size 32x32, 64x64, 128x128, 256x256, or the like, and a data unit of a character approval square whose width and height are two. The image data may be output to the encoding unit determination unit 120 for each of the at least one maximum encoding unit.

An encoding unit according to an embodiment may be characterized by a maximum size and a depth. The depth indicates the number of times the coding unit is spatially divided from the maximum coding unit. As the depth increases, the depth coding unit can be divided from the maximum coding unit to the minimum coding unit. The depth of the maximum encoding unit is the highest depth and the minimum encoding unit can be defined as the least significant encoding unit. As the depth of the maximum encoding unit increases, the size of the depth-dependent encoding unit decreases, so that the encoding unit of the higher depth may include a plurality of lower-depth encoding units.

As described above, according to the maximum size of an encoding unit, the image data of the current picture is divided into a maximum encoding unit, and each maximum encoding unit may include encoding units divided by depth. Since the maximum encoding unit according to an embodiment is divided by depth, image data of a spatial domain included in the maximum encoding unit can be hierarchically classified according to depth.

The maximum depth for limiting the total number of times the height and width of the maximum encoding unit can be hierarchically divided and the maximum size of the encoding unit may be preset.

The encoding unit determination unit 120 encodes at least one divided area in which the area of the maximum encoding unit is divided for each depth, and determines the depth at which the final encoding result is output for each of at least one of the divided areas. That is, the coding unit determination unit 120 selects the depth at which the smallest coding error occurs, and determines the coding depth as the coding depth by coding the image data in units of coding per depth for each maximum coding unit of the current picture. The determined coding depth and the image data of each coding unit are output to the output unit 130.

The image data in the maximum encoding unit is encoded based on the depth encoding unit according to at least one depth below the maximum depth, and the encoding results based on the respective depth encoding units are compared. As a result of the comparison of the encoding error of the depth-dependent encoding unit, the depth with the smallest encoding error can be selected. At least one coding depth may be determined for each maximum coding unit.

As the depth of the maximum encoding unit increases, the encoding unit is hierarchically divided and divided, and the number of encoding units increases. In addition, even if encoding units of the same depth included in one maximum encoding unit, the encoding error of each data is measured and it is determined whether or not the encoding unit is divided into lower depths. Therefore, even if the data included in one maximum coding unit has a different coding error according to the position, the coding depth can be determined depending on the position. Accordingly, one or more coding depths may be set for one maximum coding unit, and data of the maximum coding unit may be divided according to one or more coding depth encoding units.

Therefore, the encoding unit determiner 120 according to the embodiment can determine encoding units according to the tree structure included in the current maximum encoding unit. The 'encoding units according to the tree structure' according to an exemplary embodiment includes encoding units of depth determined by the encoding depth, among all depth encoding units included in the current maximum encoding unit. The coding unit of coding depth can be hierarchically determined in depth in the same coding area within the maximum coding unit, and independently determined in other areas. Similarly, the coding depth for the current area can be determined independently of the coding depth for the other area.

The maximum depth according to one embodiment is an index related to the number of divisions from the maximum encoding unit to the minimum encoding unit. The first maximum depth according to an exemplary embodiment may indicate the total number of division from the maximum encoding unit to the minimum encoding unit. The second maximum depth according to an exemplary embodiment may represent the total number of depth levels from the maximum encoding unit to the minimum encoding unit. For example, when the depth of the maximum encoding unit is 0, the depth of the encoding unit in which the maximum encoding unit is divided once may be set to 1, and the depth of the encoding unit that is divided twice may be set to 2. In this case, if the coding unit divided four times from the maximum coding unit is the minimum coding unit, since the depth levels of depth 0, 1, 2, 3 and 4 exist, the first maximum depth is set to 4 and the second maximum depth is set to 5 .

Prediction encoding and conversion of the maximum encoding unit can be performed. Likewise, predictive coding and conversion are performed on the basis of the depth coding unit for each maximum coding unit and for each depth below the maximum depth.

Since the number of coding units per depth is increased every time the maximum coding unit is divided by depth, the coding including prediction coding and conversion should be performed for every depth coding unit as the depth increases. For convenience of explanation, predictive encoding and conversion will be described based on a current encoding unit of at least one of the maximum encoding units.

The video encoding apparatus 100 according to an exemplary embodiment may select various sizes or types of data units for encoding image data. In order to encode the image data, the steps of predictive encoding, conversion, entropy encoding, and the like are performed. The same data unit may be used for all steps, and the data unit may be changed step by step.

For example, the video coding apparatus 100 can select not only a coding unit for coding image data but also a data unit different from the coding unit in order to perform predictive coding of the image data of the coding unit.

For predictive coding of the maximum coding unit, predictive coding may be performed based on a coding unit of coding depth according to an embodiment, i.e., a coding unit which is not further divided. Hereinafter, the more unfragmented encoding units that are the basis of predictive encoding will be referred to as 'prediction units'. The partition in which the prediction unit is divided may include a data unit in which at least one of the height and the width of the prediction unit and the prediction unit is divided. A partition is a data unit in which a prediction unit of a coding unit is divided, and a prediction unit may be a partition having the same size as a coding unit.

For example, if the encoding unit of size 2Nx2N (where N is a positive integer) is not further divided, it is a prediction unit of size 2Nx2N, and the size of the partition may be 2Nx2N, 2NxN, Nx2N, NxN, and the like. The partition type according to an embodiment is not limited to symmetric partitions in which the height or width of a prediction unit is divided by a symmetric ratio, but also partitions partitioned asymmetrically such as 1: n or n: 1, Partitioned partitions, arbitrary type partitions, and the like.

The prediction mode of the prediction unit may be at least one of an intra mode, an inter mode, and a skip mode. For example, intra mode and inter mode can be performed for partitions of 2Nx2N, 2NxN, Nx2N, NxN sizes. In addition, the skip mode can be performed only for a partition of 2Nx2N size. Encoding is performed independently for each prediction unit within an encoding unit, and a prediction mode having the smallest encoding error can be selected.

In addition, the video encoding apparatus 100 according to an exemplary embodiment may perform conversion of image data of an encoding unit based on not only an encoding unit for encoding image data but also a data unit different from the encoding unit. For conversion of a coding unit, the conversion may be performed based on a conversion unit having a size smaller than or equal to the coding unit. For example, the conversion unit may include a data unit for the intra mode and a conversion unit for the inter mode.

The conversion unit in the encoding unit is also recursively divided into smaller conversion units in a similar manner to the encoding unit according to the tree structure according to the embodiment, And can be partitioned according to the conversion unit.

For a conversion unit according to one embodiment, a conversion depth indicating the number of times of division until the conversion unit is divided by the height and width of the encoding unit can be set. For example, if the size of the conversion unit of the current encoding unit of size 2Nx2N is 2Nx2N, the conversion depth is set to 0 if the conversion depth is 0, if the conversion unit size is NxN, and if the conversion unit size is N / 2xN / 2, . That is, a conversion unit according to the tree structure can be set for the conversion unit according to the conversion depth.

The coding information according to the coding depth needs not only the coding depth but also prediction related information and conversion related information. Therefore, the coding unit determination unit 120 can determine not only the coding depth at which the minimum coding error is generated, but also the partition type in which the prediction unit is divided into partitions, the prediction mode for each prediction unit, and the size of the conversion unit for conversion.

The encoding unit, the prediction unit / partition, and the conversion unit determination method according to the tree structure of the maximum encoding unit according to an embodiment will be described later in detail with reference to FIGS.

The encoding unit determination unit 120 may measure the encoding error of the depth-dependent encoding unit using a Lagrangian Multiplier-based rate-distortion optimization technique.

The output unit 130 outputs, in the form of a bit stream, video data of the maximum encoding unit encoded based on at least one encoding depth determined by the encoding unit determination unit 120 and information on the depth encoding mode.

The encoded image data may be a result of encoding residual data of the image.

The information on the depth-dependent coding mode may include coding depth information, partition type information of a prediction unit, prediction mode information, size information of a conversion unit, and the like.

The coding depth information can be defined using depth division information indicating whether or not coding is performed at the lower depth coding unit without coding at the current depth. If the current depth of the current encoding unit is the encoding depth, the current encoding unit is encoded in the current depth encoding unit, so that the division information of the current depth can be defined so as not to be further divided into lower depths. On the other hand, if the current depth of the current encoding unit is not the encoding depth, the encoding using the lower depth encoding unit should be tried. Therefore, the division information of the current depth may be defined to be divided into the lower depth encoding units.

If the current depth is not the encoding depth, encoding is performed on the encoding unit divided into lower-depth encoding units. Since there are one or more lower-level coding units in the current-depth coding unit, the coding is repeatedly performed for each lower-level coding unit so that recursive coding can be performed for each coding unit of the same depth.

Since the coding units of the tree structure are determined in one maximum coding unit and information on at least one coding mode is determined for each coding unit of coding depth, information on at least one coding mode is determined for one maximum coding unit . Since the data of the maximum encoding unit is hierarchically divided according to the depth and the depth of encoding may be different for each position, information on the encoding depth and the encoding mode may be set for the data.

Accordingly, the output unit 130 according to the embodiment can allocate encoding depths and encoding information for the encoding mode to at least one of the encoding unit, the prediction unit, and the minimum unit included in the maximum encoding unit .

The minimum unit according to an exemplary embodiment is a square data unit having a minimum coding unit having the lowest coding depth divided into quadrants. The minimum unit according to an exemplary embodiment may be a maximum size square data unit that can be included in all coding units, prediction units, partition units, and conversion units included in the maximum coding unit.

For example, the encoding information output through the output unit 130 may be classified into encoding information per depth unit and encoding information per prediction unit. The encoding information for each depth coding unit may include prediction mode information and partition size information. The encoding information to be transmitted for each prediction unit includes information about the estimation direction of the inter mode, information about the reference picture index of the inter mode, information on the motion vector, information on the chroma component of the intra mode, information on the interpolation mode of the intra mode And the like.

Information on the maximum size of a coding unit defined for each picture, slice or GOP, and information on the maximum depth can be inserted into a header, a sequence parameter set, or a picture parameter set of a bitstream.

Information on the maximum size of the conversion unit allowed for the current video and information on the minimum size of the conversion unit can also be output through a header, a sequence parameter set, or a picture parameter set or the like of the bit stream. The output unit 130 may encode and output reference information, prediction information, unidirectional prediction information, slice type information including the fourth slice type, and the like related to the prediction described above with reference to FIGS.

According to the simplest embodiment of the video coding apparatus 100, the coding unit for depth is a coding unit which is half the height and width of the coding unit of one layer higher depth. That is, if the size of the current depth encoding unit is 2Nx2N, the size of the lower depth encoding unit is NxN. In addition, the current encoding unit of 2Nx2N size can include a maximum of 4 sub-depth encoding units of NxN size.

Therefore, the video encoding apparatus 100 determines the encoding unit of the optimal shape and size for each maximum encoding unit based on the size and the maximum depth of the maximum encoding unit determined in consideration of the characteristics of the current picture, Encoding units can be configured. In addition, since each encoding unit can be encoded by various prediction modes, conversion methods, and the like, an optimal encoding mode can be determined in consideration of image characteristics of encoding units of various image sizes.

Therefore, if an image having a very high image resolution or a very large data amount is encoded in units of existing macroblocks, the number of macroblocks per picture becomes excessively large. This increases the amount of compression information generated for each macroblock, so that the burden of transmission of compressed information increases and the data compression efficiency tends to decrease. Therefore, the video encoding apparatus according to an embodiment can increase the maximum size of the encoding unit in consideration of the image size, and adjust the encoding unit in consideration of the image characteristic, so that the image compression efficiency can be increased.

7 shows a block diagram of a video decoding apparatus based on a coding unit of a tree structure according to an embodiment of the present invention.

A video decoding apparatus 200 including video prediction based on a coding unit according to an exemplary embodiment includes a receiving unit 210, a video data and coding information extracting unit 220, and a video data decoding unit 230 do. For convenience of explanation, a video decoding apparatus 200 that accompanies video prediction based on a coding unit according to an exemplary embodiment is referred to as a 'video decoding apparatus 200' in short.

Definition of various terms such as coding unit, depth, prediction unit, conversion unit, and information on various coding modes for the decoding operation of the video decoding apparatus 200 according to the embodiment is the same as that of FIG. 7 and the video coding apparatus 100 Are the same as described above.

The receiving unit 210 receives and parses the bitstream of the encoded video. The image data and encoding information extracting unit 220 extracts image data encoded for each encoding unit according to the encoding units according to the tree structure according to the maximum encoding unit from the parsed bit stream and outputs the extracted image data to the image data decoding unit 230. The image data and encoding information extraction unit 220 can extract information on the maximum size of the encoding unit of the current picture from the header, sequence parameter set, or picture parameter set for the current picture.

Also, the image data and encoding information extracting unit 220 extracts information on the encoding depth and the encoding mode for the encoding units according to the tree structure for each maximum encoding unit from the parsed bit stream. The information on the extracted coding depth and coding mode is output to the image data decoding unit 230. That is, the video data of the bit stream can be divided into the maximum encoding units, and the video data decoding unit 230 can decode the video data per maximum encoding unit.

Information on the coding depth and coding mode per coding unit can be set for one or more coding depth information, and the information on the coding mode for each coding depth is divided into partition type information of the coding unit, prediction mode information, The size information of the image data, and the like. In addition, as the encoding depth information, depth-based segmentation information may be extracted.

The encoding depth and encoding mode information extracted by the image data and encoding information extracting unit 220 may be encoded in the encoding unit such as the video encoding apparatus 100 according to one embodiment, And information on the coding depth and coding mode determined to repeatedly perform coding for each unit to generate the minimum coding error. Therefore, the video decoding apparatus 200 can decode the data according to the coding scheme that generates the minimum coding error to recover the video.

The encoding information for the encoding depth and the encoding mode according to the embodiment may be allocated for a predetermined data unit among the encoding unit, the prediction unit and the minimum unit. Therefore, the image data and the encoding information extracting unit 220 may extract predetermined data Information on the coding depth and coding mode can be extracted for each unit. If information on the coding depth and the coding mode of the corresponding maximum coding unit is recorded for each predetermined data unit, the predetermined data units having the same coding depth and information on the coding mode are referred to as data units included in the same maximum coding unit .

The image data decoding unit 230 decodes the image data of each maximum encoding unit based on the information on the encoding depth and the encoding mode for each maximum encoding unit to reconstruct the current picture. That is, the image data decoding unit 230 decodes the image data encoded based on the read partition type, the prediction mode, and the conversion unit for each coding unit among the coding units according to the tree structure included in the maximum coding unit . The decoding process may include a prediction process including intra prediction and motion compensation, and an inverse process.

The image data decoding unit 230 may perform intra prediction or motion compensation according to each partition and prediction mode for each coding unit based on partition type information and prediction mode information of a prediction unit of each coding depth .

In addition, the image data decoding unit 230 may read the conversion unit information according to the tree structure for each encoding unit for inverse conversion according to the maximum encoding unit, and perform inverse conversion based on the conversion unit for each encoding unit. Through the inverse transformation, the pixel value of the spatial domain of the encoding unit can be restored.

The image data decoding unit 230 can determine the coding depth of the current maximum coding unit using the division information by depth. If the division information indicates that it is no longer divided at the current depth, then the current depth is the depth of the encoding. Therefore, the image data decoding unit 230 can decode the current depth encoding unit for the image data of the current maximum encoding unit using the partition type, the prediction mode, and the conversion unit size information of the prediction unit.

In other words, the encoding information set for the predetermined unit of data among the encoding unit, the prediction unit and the minimum unit is observed, and the data units holding the encoding information including the same division information are collected, and the image data decoding unit 230 It can be regarded as one data unit to be decoded in the same encoding mode. Information on the encoding mode can be obtained for each encoding unit determined in this manner, and decoding of the current encoding unit can be performed.

As a result, the video decoding apparatus 200 can perform recursive encoding for each maximum encoding unit in the encoding process, obtain information on the encoding unit that has generated the minimum encoding error, and use it for decoding the current picture. That is, it is possible to decode the encoded image data of the encoding units according to the tree structure determined as the optimal encoding unit for each maximum encoding unit.

Accordingly, even if an image with a high resolution or an excessively large amount of data is used, the information on the optimal encoding mode transmitted from the encoding end is used, and the image data is efficiently encoded according to the encoding unit size and encoding mode, Can be decoded and restored.

FIG. 3 illustrates a concept of an encoding unit according to an embodiment of the present invention.

An example of an encoding unit is that the size of an encoding unit is represented by a width x height, and may include 32x32, 16x16, and 8x8 from an encoding unit having a size of 64x64. The encoding unit of size 64x64 can be divided into the partitions of size 64x64, 64x32, 32x64, 32x32, and the encoding unit of size 32x32 is the partitions of size 32x32, 32x16, 16x32, 16x16 and the encoding unit of size 16x16 is the size of 16x16 , 16x8, 8x16, and 8x8, and a size 8x8 encoding unit can be divided into partitions of size 8x8, 8x4, 4x8, and 4x4.

With respect to the video data 310, the resolution is set to 1920 x 1080, the maximum size of the encoding unit is set to 64, and the maximum depth is set to 2. For the video data 320, the resolution is set to 1920 x 1080, the maximum size of the encoding unit is set to 64, and the maximum depth is set to 3. With respect to the video data 330, the resolution is set to 352 x 288, the maximum size of the encoding unit is set to 16, and the maximum depth is set to 1. The maximum depth shown in FIG. 9 represents the total number of divisions from the maximum encoding unit to the minimum encoding unit.

It is preferable that the maximum size of the coding size is relatively large in order to improve the coding efficiency as well as to accurately characterize the image characteristics when the resolution or the data amount is large. Therefore, the maximum size of the video data 310 and 320 having the higher resolution than the video data 330 can be selected to be 64. FIG.

Since the maximum depth of the video data 310 is 2, the encoding unit 315 of the video data 310 is divided into two from the maximum encoding unit having the major axis size of 64, and the depths are deepened by two layers, Encoding units. On the other hand, since the maximum depth of the video data 330 is 1, the encoding unit 335 of the video data 330 divides the encoding unit 335 having a long axis size of 16 by one time, Encoding units.

Since the maximum depth of the video data 320 is 3, the encoding unit 325 of the video data 320 divides the encoding unit 325 from the maximum encoding unit having the major axis size of 64 to 3 times, , 8 encoding units can be included. The deeper the depth, the better the ability to express detail.

4 is a block diagram of an image encoding unit based on an encoding unit according to an embodiment of the present invention.

The image encoding unit 400 according to an exemplary embodiment includes operations to encode image data in the encoding unit determination unit 120 of the video encoding device 100. [ That is, the intraprediction unit 410 performs intraprediction on the intra-mode encoding unit of the current frame 405, and the motion estimation unit 420 and the motion compensation unit 425 perform intraprediction on the current frame 405 of the inter- And a reference frame 495, as shown in FIG.

The data output from the intraprediction unit 410, the motion estimation unit 420 and the motion compensation unit 425 are output as quantized transform coefficients through the transform unit 430 and the quantization unit 440. The quantized transform coefficients are reconstructed into spatial domain data through the inverse quantization unit 460 and the inverse transform unit 470 and the data of the reconstructed spatial domain is passed through the deblocking unit 480 and the offset adjustment unit 490, And output to the reference frame 495. The quantized transform coefficient may be output to the bitstream 455 via the entropy encoding unit 450.

The motion estimation unit 420, the motion compensation unit 425, and the conversion unit 420, which are the components of the image encoding unit 400, to be applied to the video encoding apparatus 100 according to one embodiment. The quantization unit 440, the entropy encoding unit 450, the inverse quantization unit 460, the inverse transform unit 470, the deblocking unit 480 and the offset adjustment unit 490 are provided with a maximum depth It is necessary to perform operations based on each encoding unit among the encoding units according to the tree structure.

In particular, the intra prediction unit 410, the motion estimation unit 420, and the motion compensation unit 425 compute the maximum size and the maximum depth of the current maximum encoding unit, And the prediction mode, and the conversion unit 430 determines the size of the conversion unit in each coding unit among the coding units according to the tree structure.

5 is a block diagram of an image decoding unit based on an encoding unit according to an embodiment of the present invention.

The bitstream 505 passes through the parsing unit 510 and the encoded image data to be decoded and the encoding-related information necessary for decoding are parsed. The encoded image data is output as inverse quantized data through the entropy decoding unit 520 and the inverse quantization unit 530, and the image data in the spatial domain is restored via the inverse transform unit 540.

The intra-prediction unit 550 performs intraprediction on the intra-mode encoding unit for the video data in the spatial domain, and the motion compensating unit 560 performs intra-prediction on the intra-mode encoding unit using the reference frame 585 And performs motion compensation for the motion compensation.

The data in the spatial domain that has passed through the intra prediction unit 550 and the motion compensation unit 560 may be post-processed through the deblocking unit 570 and the offset adjusting unit 580 and output to the restoring frame 595. Further, the post-processed data via the deblocking unit 570 and the offset adjusting unit 580 may be output as a reference frame 585. [

In order to decode the image data in the image data decoding unit 230 of the video decoding apparatus 200, operations after the parsing unit 510 of the image decoding unit 500 according to the embodiment may be performed.

A parsing unit 510, an entropy decoding unit 520, an inverse quantization unit 530, and an inverse transform unit 540, which are components of the video decoding unit 500, in order to be applied to the video decoding apparatus 200 according to one embodiment. The intraprediction unit 550, the motion compensation unit 560, the deblocking unit 570 and the offset adjustment unit 580 all have to perform operations based on the encoding units according to the tree structure for each maximum encoding unit .

In particular, the intraprediction unit 550 and the motion compensation unit 560 determine the partition and prediction mode for each coding unit according to the tree structure, and the inverse transform unit 540 determines the size of the conversion unit for each coding unit .

FIG. 6 illustrates a depth-based encoding unit and a partition according to an exemplary embodiment of the present invention.

The video encoding apparatus 100 and the video decoding apparatus 200 according to an exemplary embodiment use a hierarchical encoding unit to consider an image characteristic. The maximum height, width, and maximum depth of the encoding unit may be adaptively determined according to the characteristics of the image, or may be variously set according to the demand of the user. The size of each coding unit may be determined according to the maximum size of a predetermined coding unit.

The hierarchical structure 600 of the encoding unit according to an embodiment shows a case where the maximum height and width of the encoding unit is 64 and the maximum depth is 3. In this case, the maximum depth indicates the total number of division from the maximum encoding unit to the minimum encoding unit. Since the depth is deeper along the vertical axis of the hierarchical structure 600 of the encoding unit according to the embodiment, the height and width of the encoding unit for each depth are divided. In addition, along the horizontal axis of the hierarchical structure 600 of encoding units, prediction units and partitions serving as the basis of predictive encoding of each depth-dependent encoding unit are shown.

That is, the coding unit 610 is the largest coding unit among the hierarchical structures 600 of the coding units and has a depth of 0, and the size of the coding units, that is, the height and the width, is 64x64. There are a coding unit 620 having a depth 1 along a vertical axis and a depth 1 with a size of 32x32, a coding unit 630 having a depth 16x16 with a depth 16 and a coding unit 640 having a depth 8 having a size 8x8. 3 encoding unit 640 is the minimum encoding unit.

Prediction units and partitions of coding units are arranged along the horizontal axis for each depth. That is, if the encoding unit 610 having a depth 0 size of 64x64 is a prediction unit, the prediction unit is a partition 610 having a size of 64x64, a partition 612 having a size 64x32, 32x64 partitions 614, and size 32x32 partitions 616. [

Likewise, the prediction unit of the 32x32 coding unit 620 having the depth 1 is the partition 620 of the size 32x32, the partitions 622 of the size 32x16, the partition 622 of the size 16x32 included in the coding unit 620 of the size 32x32, And a partition 626 of size 16x16.

Likewise, the prediction unit of the 16x16 encoding unit 630 of depth 2 is divided into a partition 630 of size 16x16, partitions 632 of size 16x8, partitions 632 of size 8x16 included in the encoding unit 630 of size 16x16, (634), and partitions (636) of size 8x8.

Likewise, the prediction unit of the 8x8 encoding unit 640 of depth 3 is a partition 640 of size 8x8, partitions 642 of size 8x4, partitions 642 of size 4x8 included in the encoding unit 640 of size 8x8, 644, and a partition 646 of size 4x4.

Finally, a coding unit 640 of size 8x8 with depth 3 is the minimum coding unit and the lowest-depth coding unit.

The encoding unit determination unit 120 of the video encoding apparatus 100 according to an exemplary embodiment of the present invention determines encoding depths of encoding units of the respective depths included in the maximum encoding unit 610 Encoding is performed.

The number of coding units per depth to include data of the same range and size increases as the depth of the coding unit increases. For example, for data containing one coding unit at depth 1, four coding units at depth 2 are required. Therefore, in order to compare the encoding results of the same data by depth, they should be encoded using a single depth 1 encoding unit and four depth 2 encoding units, respectively.

For each depth-of-field coding, encoding is performed for each prediction unit of the depth-dependent coding unit along the horizontal axis of the hierarchical structure 600 of the coding unit, and a representative coding error, which is the smallest coding error at the corresponding depth, is selected . In addition, depths are deepened along the vertical axis of the hierarchical structure 600 of encoding units, and the minimum encoding errors can be retrieved by comparing the representative encoding errors per depth by performing encoding for each depth. The depth and partition at which the minimum coding error occurs among the maximum coding units 610 can be selected as the coding depth and the partition type of the maximum coding unit 610. [

FIG. 7 shows a relationship between an encoding unit and a conversion unit according to an embodiment of the present invention.

The video coding apparatus 100 or the video decoding apparatus 200 according to an embodiment encodes or decodes an image in units of coding units smaller than or equal to the maximum coding unit for each maximum coding unit. The size of the conversion unit for conversion during the encoding process can be selected based on a data unit that is not larger than each encoding unit.

For example, in the video encoding apparatus 100 or the video encoding apparatus 200 according to an embodiment, when the current encoding unit 710 is 64x64 size, the 32x32 conversion unit 720 The conversion can be performed.

In addition, the data of the 64x64 encoding unit 710 is converted into 32x32, 16x16, 8x8, and 4x4 conversion units each having a size of 64x64 or smaller, and then a conversion unit having the smallest error with the original is selected .

FIG. 8 illustrates depth-specific encoding information, in accordance with an embodiment of the present invention.

The output unit 130 of the video encoding apparatus 100 according to one embodiment includes information on the encoding mode, information 800 relating to the partition type, information 810 relating to the prediction mode for each encoding unit of each encoding depth, , And information 820 on the conversion unit size may be encoded and transmitted.

The partition type information 800 represents information on the type of partition in which the prediction unit of the current encoding unit is divided, as a data unit for predictive encoding of the current encoding unit. For example, the current encoding unit CU_0 of size 2Nx2N may be any one of a partition 802 of size 2Nx2N, a partition 804 of size 2NxN, a partition 806 of size Nx2N, and a partition 808 of size NxN And can be divided and used. In this case, the information 800 regarding the partition type of the current encoding unit indicates one of a partition 802 of size 2Nx2N, a partition 804 of size 2NxN, a partition 806 of size Nx2N, and a partition 808 of size NxN .

The prediction mode information 810 indicates a prediction mode of each partition. For example, it is determined whether the partition indicated by the information 800 relating to the partition type is predictive-encoded in one of the intra mode 812, the inter mode 814, and the skip mode 816 through the prediction mode information 810 Can be set.

In addition, the information 820 on the conversion unit size indicates whether to perform conversion based on which conversion unit the current encoding unit is to be converted. For example, the conversion unit may be one of a first intra-conversion unit size 822, a second intra-conversion unit size 824, a first inter-conversion unit size 826, have.

The video data and encoding information extracting unit 210 of the video decoding apparatus 200 according to one embodiment is configured to extract the information 800 about the partition type, the information 810 about the prediction mode, Information 820 on the unit size can be extracted and used for decoding.

FIG. 9 shows a depth encoding unit according to an embodiment of the present invention.

Partition information may be used to indicate changes in depth. The division information indicates whether the current-depth encoding unit is divided into lower-depth encoding units.

The prediction unit 910 for predicting the coding unit 900 having the depth 0 and 2N_0x2N_0 size includes a partition type 912 of 2N_0x2N_0 size, a partition type 914 of 2N_0xN_0 size, a partition type 916 of N_0x2N_0 size, N_0xN_0 Size partition type 918. < RTI ID = 0.0 > Only the partitions 912, 914, 916, and 918 in which the prediction unit is divided at the symmetric ratio are exemplified, but the partition type is not limited to the above, and may be an asymmetric partition, an arbitrary type partition, . ≪ / RTI >

For each partition type, predictive encoding should be repeatedly performed for each partition of size 2N_0x2N_0, two 2N_0xN_0 partitions, two N_0x2N_0 partitions, and four N_0xN_0 partitions. For a partition of size 2N_0x2N_0, size N_0x2N_0, size 2N_0xN_0 and size N_0xN_0, predictive coding can be performed in intra mode and inter mode. The skip mode can be performed only on the partition of size 2N_0x2N_0 with predictive coding.

If the encoding error caused by one of the partition types 912, 914, and 916 of the sizes 2N_0x2N_0, 2N_0xN_0 and N_0x2N_0 is the smallest, there is no need to further divide into lower depths.

If the coding error by the partition type 918 of the size N_0xN_0 is the smallest, the depth 0 is changed to 1 and divided (920), and the coding unit 930 of the partition type of the depth 2 and the size N_0xN_0 is repeatedly encoded The minimum coding error can be retrieved.

A prediction unit 940 for predicting the coding unit 930 of the depth 1 and the size 2N_1x2N_1 (= N_0xN_0) includes a partition type 942 of size 2N_1x2N_1, a partition type 944 of size 2N_1xN_1, a partition type 942 of size N_1x2N_1 (946), and a partition type 948 of size N_1xN_1.

If the encoding error by the partition type 948 having the size N_1xN_1 size is the smallest, the depth 1 is changed to the depth 2 and divided (950), and repeatedly performed on the encoding units 960 of the depth 2 and the size N_2xN_2 Encoding can be performed to search for the minimum coding error.

If the maximum depth is d, the depth-based coding unit is set up to the depth d-1, and the division information can be set up to the depth d-2. That is, when the encoding is performed from the depth d-2 to the depth d-1, the prediction encoding of the encoding unit 980 of the depth d-1 and the size 2N_ (d-1) x2N_ (d- The prediction unit 990 for the size 2N_ (d-1) x2N_ (d-1) includes a partition type 992 of size 2N_ A partition type 998 of N_ (d-1) x2N_ (d-1), and a partition type 998 of size N_ (d-1) xN_ (d-1).

(D-1) x2N_ (d-1), two size 2N_ (d-1) xN_ (d-1) partitions, and two sizes N_ (d-1) and the partition of four sizes N_ (d-1) xN_ (d-1), the partition type in which the minimum coding error occurs can be retrieved .

Even if the coding error by the partition type 998 of the size N_ (d-1) xN_ (d-1) is the smallest, since the maximum depth is d, the coding unit CU_ (d-1) of the depth d- The coding depth for the current maximum coding unit 900 is determined as the depth d-1, and the partition type can be determined as N_ (d-1) xN_ (d-1). Also, since the maximum depth is d, the division information is not set for the encoding unit 952 of the depth d-1.

The data unit 999 may be referred to as the 'minimum unit' for the current maximum encoding unit. The minimum unit according to an exemplary embodiment may be a quadrangle data unit having a minimum coding unit having the lowest coding depth divided into quadrants. Through the iterative coding process, the video coding apparatus 100 according to an embodiment compares the coding errors of the coding units 900 to determine the coding depth, selects the depth at which the smallest coding error occurs, determines the coding depth, The corresponding partition type and the prediction mode can be set to the coding mode of the coding depth.

In this way, the minimum coding error of each of the depths 0, 1, ..., d-1, and d is compared and the depth with the smallest error is selected to be determined as the coding depth. The coding depth, and the partition type and prediction mode of the prediction unit can be encoded and transmitted as information on the encoding mode. In addition, since the coding unit must be divided from the depth 0 to the coding depth, only the division information of the coding depth is set to '0', and the division information by depth is set to '1' except for the coding depth.

The video data and encoding information extracting unit 220 of the video decoding apparatus 200 according to an exemplary embodiment extracts information on the encoding depth and the prediction unit for the encoding unit 900 and uses the information to extract the encoding unit 912 . The video decoding apparatus 200 according to an exemplary embodiment of the present invention uses division information by depth to grasp the depth with the division information of '0' as a coding depth and can use it for decoding using information on the coding mode for the corresponding depth have.

FIGS. 10, 11 and 12 show the relationship between an encoding unit, a prediction unit, and a conversion unit according to an embodiment of the present invention.

The coding unit 1010 is coding units for coding depth determined by the video coding apparatus 100 according to the embodiment with respect to the maximum coding unit. The prediction unit 1060 is a partition of prediction units of each coding depth unit in the coding unit 1010, and the conversion unit 1070 is a conversion unit of each coding depth unit.

When the depth of the maximum encoding unit is 0, the depth of the encoding units 1012 and 1054 is 1 and the depth of the encoding units 1014, 1016, 1018, 1028, 1050, The coding units 1020, 1022, 1024, 1026, 1030, 1032 and 1048 have a depth of 3 and the coding units 1040, 1042, 1044 and 1046 have a depth of 4.

Some partitions 1014, 1016, 1022, 1032, 1048, 1050, 1052, and 1054 among the prediction units 1060 are in the form of a segment of a coding unit. That is, the partitions 1014, 1022, 1050 and 1054 are 2NxN partition types, the partitions 1016, 1048 and 1052 are Nx2N partition type, and the partition 1032 is NxN partition type. The prediction units and the partitions of the depth-dependent coding units 1010 are smaller than or equal to the respective coding units.

The image data of a part 1052 of the conversion units 1070 is converted or inversely converted into a data unit smaller in size than the encoding unit. The conversion units 1014, 1016, 1022, 1032, 1048, 1050, 1052, and 1054 are data units of different sizes or types when compared with the prediction units and the partitions of the prediction units 1060. In other words, the video coding apparatus 100 according to the embodiment and the video decoding apparatus 200 according to the embodiment can perform the intra prediction / motion estimation / motion compensation operation for the same coding unit and the conversion / Each can be performed on a separate data unit basis.

Thus, for each maximum encoding unit, the encoding units are recursively performed for each encoding unit hierarchically structured in each region, and the optimal encoding unit is determined, so that encoding units according to the recursive tree structure can be constructed. The encoding information may include division information for the encoding unit, partition type information, prediction mode information, and conversion unit size information. Table 1 below shows an example that can be set in the video encoding apparatus 100 according to the embodiment and the video decoding apparatus 200 according to an embodiment.

Partition information 0 (encoding for the encoding unit of size 2Nx2N of current depth d) Partition information 1 Prediction mode Partition type Conversion unit size For each sub-depth d + 1 encoding units, Intra
Inter

Skip (2Nx2N only) Symmetrical partition type Asymmetric partition type Conversion unit partition information 0 Conversion unit
Partition information 1 2Nx2N
2NxN
Nx2N
NxN 2NxnU
2NxnD
nLx2N
nRx2N 2Nx2N NxN
(Symmetrical partition type)

N / 2xN / 2
(Asymmetric partition type)

The output unit 130 of the video encoding apparatus 100 according to an exemplary embodiment outputs encoding information for encoding units according to the tree structure and outputs the encoding information to the encoding information extracting unit 220 can extract the encoding information for the encoding units according to the tree structure from the received bitstream.

The division information indicates whether the current encoding unit is divided into low-depth encoding units. If the division information of the current depth d is 0, since the depth at which the current encoding unit is not further divided into the current encoding unit is the encoding depth, the partition type information, prediction mode, and conversion unit size information are defined . When it is necessary to further divide by one division according to the division information, encoding should be performed independently for each of four divided sub-depth coding units.

The prediction mode may be represented by one of an intra mode, an inter mode, and a skip mode. Intra mode and inter mode can be defined in all partition types, and skip mode can be defined only in partition type 2Nx2N.

The partition type information indicates symmetrical partition types 2Nx2N, 2NxN, Nx2N and NxN in which the height or width of the predicted unit is divided into symmetric proportions and asymmetric partition types 2NxnU, 2NxnD, nLx2N, and nRx2N divided by the asymmetric ratio . Asymmetric partition types 2NxnU and 2NxnD are respectively divided into heights 1: 3 and 3: 1, and asymmetric partition types nLx2N and nRx2N are respectively divided into widths of 1: 3 and 3: 1.

The conversion unit size can be set to two kinds of sizes in the intra mode and two kinds of sizes in the inter mode. That is, if the conversion unit division information is 0, the size of the conversion unit is set to the size 2Nx2N of the current encoding unit. If the conversion unit division information is 1, a conversion unit of the size where the current encoding unit is divided can be set. Also, if the partition type for the current encoding unit of size 2Nx2N is a symmetric partition type, the size of the conversion unit may be set to NxN, or N / 2xN / 2 if it is an asymmetric partition type.

The encoding information of the encoding units according to the tree structure according to an exemplary embodiment may be allocated to at least one of encoding units, prediction units, and minimum unit units of the encoding depth. The coding unit of the coding depth may include one or more prediction units and minimum units having the same coding information.

Therefore, if encoding information held in adjacent data units is checked, it can be confirmed whether or not the encoded information is included in the encoding unit of the same encoding depth. In addition, since the encoding unit of the encoding depth can be identified by using the encoding information held by the data unit, the distribution of encoding depths within the maximum encoding unit can be inferred.

Therefore, in this case, when the current encoding unit is predicted with reference to the neighboring data unit, the encoding information of the data unit in the depth encoding unit adjacent to the current encoding unit can be directly referenced and used.

In another embodiment, when predictive encoding is performed with reference to a current encoding unit with reference to a surrounding encoding unit, data adjacent to the current encoding unit in the depth encoding unit is encoded using the encoding information of adjacent encoding units The surrounding encoding unit may be referred to by being searched.

Fig. 13 shows the relationship between the encoding unit, the prediction unit and the conversion unit according to the encoding mode information in Table 1. Fig.

The maximum coding unit 1300 includes coding units 1302, 1304, 1306, 1312, 1314, 1316, and 1318 of the coding depth. Since one of the encoding units 1318 is a coding unit of the encoding depth, the division information may be set to zero. The partition type information of the encoding unit 1318 of the size 2Nx2N is the partition type information of the partition type 2Nx2N 1322, 2NxN 1324, Nx2N 1326, NxN 1328, 2NxnU 1332, 2NxnD 1334, nLx2N 1336, And < RTI ID = 0.0 > nRx2N 1338 < / RTI >

The TU size flag is a kind of conversion index, and the size of the conversion unit corresponding to the conversion index can be changed according to the prediction unit type or partition type of the coding unit.

For example, when the partition type information is set to one of the symmetric partition types 2Nx2N 1322, 2NxN 1324, Nx2N 1326 and NxN 1328, if the conversion unit division information is 0, the conversion unit of size 2Nx2N 1342) is set, and if the conversion unit division information is 1, the conversion unit 1344 of size NxN can be set.

When the partition type information is set to one of the asymmetric partition types 2NxnU 1332, 2NxnD 1334, nLx2N 1336 and nRx2N 1338, if the TU size flag is 0, the conversion unit of size 2Nx2N 1352) is set, and if the conversion unit division information is 1, a conversion unit 1354 of size N / 2xN / 2 can be set.

The TU size flag described above with reference to FIG. 13 is a flag having a value of 0 or 1, but the conversion unit division information according to the embodiment is not limited to a 1-bit flag and may be 0 , 1, 2, 3, etc., and the conversion unit may be divided hierarchically. The conversion unit partition information can be used as an embodiment of the conversion index.

In this case, if the conversion unit division information according to the embodiment is used together with the maximum size of the conversion unit and the minimum size of the conversion unit, the size of the conversion unit actually used can be expressed. The video encoding apparatus 100 according to an exemplary embodiment may encode the maximum conversion unit size information, the minimum conversion unit size information, and the maximum conversion unit division information. The encoded maximum conversion unit size information, the minimum conversion unit size information, and the maximum conversion unit division information may be inserted into the SPS. The video decoding apparatus 200 according to an exemplary embodiment can use the maximum conversion unit size information, the minimum conversion unit size information, and the maximum conversion unit division information for video decoding.

For example, if (a) the current encoding unit is 64x64 and the maximum conversion unit size is 32x32, (a-1) when the conversion unit division information is 0, the size of the conversion unit is 32x32, When the division information is 1, the size of the conversion unit is 16x16, (a-3) When the conversion unit division information is 2, the size of the conversion unit can be set to 8x8.

In another example, (b) if the current encoding unit is 32x32 and the minimum conversion unit size is 32x32, the size of the conversion unit may be set to 32x32 when the conversion unit division information is 0, Since the size can not be smaller than 32x32, further conversion unit division information can not be set.

As another example, (c) if the current encoding unit is 64x64 and the maximum conversion unit division information is 1, the conversion unit division information may be 0 or 1, and other conversion unit division information can not be set.

Therefore, when the maximum conversion unit division information is defined as 'MaxTransformSizeIndex', the minimum conversion unit size is defined as 'MinTransformSize', and the conversion unit size when the conversion unit division information is 0 is defined as 'RootTuSize', the minimum conversion unit The size 'CurrMinTuSize' can be defined as the following relation (1).

CurrMinTuSize

= max (MinTransformSize, RootTuSize / (2 ^ MaxTransformSizeIndex)) (1)

'RootTuSize', which is the conversion unit size when the conversion unit division information is 0 as compared with the minimum conversion unit size 'CurrMinTuSize' possible in the current encoding unit, can represent the maximum conversion unit size that can be adopted by the system. That is, according to the relational expression (1), 'RootTuSize / (2 ^ MaxTransformSizeIndex)' is obtained by dividing 'RootTuSize', which is the conversion unit size in the case where the conversion unit division information is 0, by the number corresponding to the maximum conversion unit division information Unit size, and 'MinTransformSize' is the minimum conversion unit size, so a smaller value of these may be the minimum conversion unit size 'CurrMinTuSize' that is currently available in the current encoding unit.

The maximum conversion unit size RootTuSize according to an exemplary embodiment may vary depending on the prediction mode.

For example, if the current prediction mode is the inter mode, RootTuSize can be determined according to the following relation (2). In the relation (2), 'MaxTransformSize' indicates the maximum conversion unit size and 'PUSize' indicates the current prediction unit size.

RootTuSize = min (MaxTransformSize, PUSize) (2)

That is, if the current prediction mode is the inter mode, 'RootTuSize' which is the conversion unit size when the conversion unit division information is 0 can be set to a smaller value of the maximum conversion unit size and the current prediction unit size.

If the prediction mode of the current partition unit is the intra mode, if the prediction mode is the mode, 'RootTuSize' can be determined according to the following relation (3). 'PartitionSize' represents the size of the current partition unit.

RootTuSize = min (MaxTransformSize, PartitionSize) (3)

That is, if the current prediction mode is the intra mode, 'RootTuSize' which is the conversion unit size when the conversion unit division information is 0 can be set to a smaller value among the maximum conversion unit size and the size of the current partition unit.

However, it should be noted that the present maximum conversion unit size 'RootTuSize' according to one embodiment that varies according to the prediction mode of the partition unit is only one embodiment, and the factor for determining the current maximum conversion unit size is not limited thereto.

The maximum encoding unit including the encoding units of the tree structure described above with reference to FIGS. 1 to 13 may be a coding block tree, a block tree, a root block tree, a coding tree, a coding route, Tree trunks, and so on.

Hereinafter, a method and apparatus for encoding and decoding a residual signal based on a coding unit of a tree structure will be described with reference to Figs. 14 to 25. Fig.

FIG. 14 is a block diagram illustrating a configuration of a video encoding apparatus according to an embodiment. FIG. 15 is a block diagram illustrating the configuration of a predictive encoding unit 1410 of FIG.

14 and 15, a video encoding apparatus 1400 according to an embodiment includes a predictive encoding unit 1410, a differential residual information generating unit 1420, and a differential residual signal generating unit 1430 .

The predictive encoding unit 1410 divides each picture into a maximum encoding unit having the maximum size, divides the maximum encoding unit into at least one encoding unit, and then predictively encodes each picture based on the encoding unit. Specifically, the dividing unit 1411 divides a picture into a maximum coding unit and generates a coding unit by dividing the maximum coding unit according to the depth indicating the number of spatial division of the maximum coding unit as shown in Figs. 1 to 13 . The prediction unit 1412 generates a prediction value using a prediction unit that is included in the coding unit and is a data unit that is independent of the coding unit. The prediction mode of the prediction unit may be one of an intra mode, an inter mode, a skip mode, and a direct mode. The predicting unit 1412 generates a prediction value according to each prediction mode independently for each prediction unit included in the coding unit and determines the prediction mode having the minimum coding error as the prediction mode of the prediction unit. Further, the subtractor 1413 calculates the difference between the predicted value of the predictive unit generated by the predictor 1413 and the input signal, and generates a residual signal. The predictive encoding unit 1410 generates a residual signal for each prediction unit included in the encoding unit and generates a residual signal of the encoding unit.

The video coding apparatus 1400 according to an embodiment generates a differential residual signal by calculating a residual difference value between adjacent pixels in a predetermined direction without encoding the residual signal as it is, send. The reason for generating the differential residual signal in this way is to reduce the size of the residual signal to improve the compression ratio. A method of generating the differential residual signal will be described later with reference to FIG. 16 to FIG.

The differential residual control information generation unit 1420 generates differential residual control information of the residual signal included in the coding unit based on at least one layer information among the conversion units used for the conversion of the coding unit, Lt; / RTI >

As the layer information, at least one of the size of the encoding unit, the size of the prediction unit, the size of the conversion unit, the type of the prediction mode applied to the prediction unit, and the tree structure type of the prediction unit or conversion unit included in the encoding unit can be used. The control information includes information on a data unit in which a differential residual signal is generated among an encoding unit, a prediction unit, and a conversion unit, size information of a data unit in which a differential residual signal is generated, Flag information indicating whether or not to use the signal, and information regarding a generation direction of the differential residual signal.

Specifically, the differential residual control information generator 1420 generates control information on how to generate the differential residual signal based on the layer information. For example, the differential residual control information generator 1420 determines which data unit of the encoding unit, the prediction unit, and the conversion unit is to be used to generate the differential residual signal, and generates the determined residual signal It is possible to output information on a data unit as control information.

The differential residual control information generator 1420 determines the size of the data unit for which the differential residual signal is generated based on the size information of the encoding unit, the prediction unit, and the conversion unit, and stores the size information of the determined data unit It can be outputted as control information. The size of the data unit in which the differential residual signal is generated can be set to a predetermined range. For example, the differential residual control information generator 1420 can determine that a differential residual signal is generated only for data units having a size between 8x8 and 16x16. As another example, the differential residual control information generator 1420 may determine the type of the data unit in which the differential residual signal is to be generated among the encoding unit, the prediction unit, and the conversion units, It can be determined that the differential residual signal is generated only for the data units in the frame.

Also, the differential residual control information generator 1420 can set control information as to whether to use the differential residual signal of the adjacent data unit at the time of generating the differential residual signal. In other words, the differential residual control information generator 1420 determines whether to generate the differential residual signal only within a predetermined data unit, or to refer to the differential residual signal of another adjacent data unit, It is possible to determine whether to generate a differential residual signal.

In this manner, the differential residual control information generator 1420 determines the generation method of the differential residual signal and outputs information about the determined differential residual signal generation method as control information.

The differential residual signal generator 1430 receives the control information output from the differential residual control information generator 1420 and generates a differential residual signal of the residual signal included in the coding unit based on the control information And generates a differential residual signal of the residual signal included in the coding unit according to the determined differential residual signal generating method.

The differential residual signal generated by the differential residual signal generating unit 1430 can be directly encoded through a lossless method through entropy encoding without any additional conversion and quantization, or can be encoded through conversion, quantization, and entropy encoding.

Differential residual signals will now be described with reference to FIGS. 16 to 18. FIG.

16 is a diagram illustrating a residual signal of an encoding unit according to an embodiment of the present invention.

As described above, the predictive encoding unit 1410 can generate the residual signal 1600 which is the difference between the predictive signal and the original signal of the encoding unit generated using the predictive unit. In Fig. 16, the residual signals of the pixels located in the x-th row and the y-th column are denoted by r _{x , y} .

The differential residual signal can be obtained by calculating the difference value of the residual signal of the adjacent pixels along the predetermined direction. For example, the differential residual signal can be obtained by performing DPCM (Differential Pulse Code Modulation) in the horizontal direction or the vertical direction using the residual signal of each pixel.

FIG. 17 illustrates a process of generating a differential residual signal in the horizontal direction according to an embodiment of the present invention, and FIG. 18 illustrates a process of generating a differential residual signal in the vertical direction according to the present invention.

Referring to FIG. 17, the differential residual signal 1700 may be generated in the horizontal direction by calculating the difference value of the residual signals of the pixels adjacent in the horizontal direction. Let r ' _{x , y} denote the differential residual signal of the pixel located in the x-th row and the y-th column _, and when generating the differential residual signal in the horizontal direction, r' _{x , y} is obtained by the following equation .

If adjacent without using the residual signal of the coded unit using only the residual signal in the coding unit, first the difference between the residual signal of the in-pixel columns, that _{is, r '0, 0, r} ' 1, 0, r '2 _{, 0, ..., r '15} , 0 has the original residual signal value. In other words, r _{is' N, 0 = r N,} 0 (N = 0,1,2, ..., 15).

Referring to FIG. 18, the differential residual signal 1800 may be generated in the vertical direction by calculating the difference value of the residual signals of pixels adjacent in the vertical direction. When generating the differential residual signal in the vertical direction, r ' _{x , y} can be obtained by the following equation (2).

₀ ', r' _{0 , 1} , r ' _{0 , 0} ' _{, 0} ' _{, 0} ' _{, 0} ' _{, 0} ' _{, 1} ' _{, 1} ', _{and 0} 'of the pixels located in the first row are used when only the residual signal in the encoding unit is used without using the residual signal of the adjacent encoding unit _{, 2} , ..., r ' _{0 , 15} have the original residual signal value. In other words, r ' _{0 , N} = r _{0 , N} (N = 0, 1, 2, ..., 15).

The direction in which the differential residual signal is generated is not limited to the horizontal and vertical directions and can be changed. For example, the differential residual signal may be obtained by calculating the difference value of the residual signal between adjacent pixels in the 45 degree and 135 degree directions. That is, the differential residual signal is obtained by calculating the difference value between the residual signal of one pixel among the pixels located on the upper left side, the upper left side, the lower left side and the lower right side of the current pixel and the residual signal of the current pixel It is possible. Further, the direction of generating the differential residual signal may be determined based on the intra prediction direction of the pixels included in the data unit. For example, if the current data unit is intra-predicted in the horizontal direction, the differential residual signal may be generated in the horizontal direction. The direction in which the differential residual signal is generated may be set in advance on the encoding side and the decoding side in advance.

As described above, the differential residual control information generating unit 1420 determines the generation method of the differential residual signal based on the layer information, and outputs information about the determined generation method as control information. Hereinafter, a process of determining the generation method of the differential residual signal based on the hierarchical information of the encoding unit, the prediction unit, and the conversion unit will be described.

19A is an example of a coding unit 1910 of a tree structure obtained by dividing the maximum coding unit. FIG. 19B is an example of a prediction unit 1920 for predictive coding of the coding unit 1910 included in the maximum coding unit of FIG. 19A. FIG. 19C is an example of a change unit 1930 for conversion of the encoding unit 1910 of FIG. 19A.

As described above, an optimal encoding unit is determined by performing recursive encoding using the encoding units of a hierarchical structure for each maximum encoding unit, and an optimal prediction unit and conversion unit for prediction and conversion of each encoding unit are determined Can be determined.

When the coding unit 1910, the prediction unit 1920 and the conversion unit 1930 are determined for the maximum coding unit, the differential residual control information generating unit 1420 generates a coding unit 1910, a prediction unit 1920, A method of generating a differential residual signal based on the hierarchical information of at least one data unit among the units 1930 can be determined. For example, the differential residual control information generator 1420 can determine which data unit of the coding unit, the prediction unit, and the conversion unit is to be used to generate the differential residual signal. The encoding unit 1910, the prediction unit 1920, and the conversion unit 1930 according to the embodiment have independent boundaries, and the boundaries of the respective data units may not coincide with each other. 19A to 19C, an encoding unit 1911 may be divided into two prediction units 1921 and 1922, and the encoding unit 1912 may include two prediction units 1923 , 1924). ≪ / RTI > The encoding unit 1911 may be divided into four conversion units 1935 to 1938 and converted into the four conversion units 1939 to 1942, The encoding unit 1913 can be divided into four conversion units 1931 to 1934 and converted. Accordingly, the differential residual control information generator 1420 can determine which data unit of the coding unit, the prediction unit, and the conversion unit is to be used to generate the differential residual signal. For example, when it is determined to generate the differential residual signal based on the prediction unit of FIG. 19B, a differential residual signal is generated using the residual signal included in the prediction unit for each prediction unit shown in FIG. 19B .

Also, the differential residual control information generator 1420 can determine the size of the data unit in which the differential residual signal is generated based on the size information of the encoding unit, the prediction unit, and the conversion unit. For example, the differential residual control information generator 1420 can determine to generate a differential residual signal only for a data unit of a specific size. Also, the differential residual control information generator 1420 can determine to generate a differential residual signal only for data units within a predetermined size range. For example, when the differential residual signal is set to be generated only for the encoding units within the range of 4x4 to 16x16 in FIG. 19A, the differential residual signal is not generated for the encoding units 1911, 1912, and 1913, A differential residual signal is generated.

As described above, the differential residual control information generator 1420 can set control information as to whether or not to use the differential residual signal of the adjacent data unit when generating the differential residual signal.

20A is a diagram illustrating a method of generating a differential residual signal by using a residual signal of a data unit adjacent in the vertical direction. FIG. 20B illustrates a method of generating a differential residual signal by using a residual signal of a data unit adjacent in the horizontal direction Fig.

Referring to FIG. 20A, a residual residual signal of the most-run pixels of the current data unit 2000 can be obtained by using the residual signal 2010 of the neighboring data units adjacent in the vertical direction. The differential residual signal of the best-run can be obtained by calculating the difference value between the residual of the pixel located in the current data unit best-run and the residual of the pixel located in the upper-side peripheral unit. Similarly, referring to FIG. 20B, the residual residual signal of the pixels in the leftmost column of the current data unit 2020 can be obtained using the residual signal 2030 of the neighboring data units adjacent in the horizontal direction. However, in the case of using the residual signal of the peripheral data unit, the current data unit has dependency on the processing of the peripheral data unit, so that the parallel processing can not be performed and the calculation time required for calculation of the differential residual signal is increased . Therefore, the differential residual control information generator 1420 can set control information (enable_use_neighboring_redisual_flag) as to whether to use the residual signal of the adjacent data unit when generating the differential residual signal. When enable_use_neighboring_redisual_flag is 0, it indicates that the residual signal of the peripheral data unit is not used in generation of the differential residual signal. When enable_use_neighboring_redisual_flag is 1, it indicates that the residual signal of the peripheral data unit is used in generating the differential residual signal.

The control information generated by the differential residual control information generation unit 1420 may be included in one of a VPS (Video Parameter Set), an SPS (Sequence Parameter Set), a PPS (Picture Parameter Set) and a slice segment, have. When the control information is not separately transmitted to the decoding side, the decoding side generates control information on the generation of the differential residual signal in the same manner as on the encoding side, and restores the residual signal from the differential residual signal based on the generated control information can do. Even if the control information is not separately transmitted to the decoding side, a flag (enable_RDPCM_flag) indicating whether to use the differential residual signal is transmitted. When enable_RDPCM_flag is 1, it indicates that the encoded data is generated by using the differential residual signal instead of the residual signal. When enable_RDPCM_flag is 0, it indicates that the encoded data is a general residual signal instead of the differential residual signal.

As described above, according to the embodiments of the present invention, video is encoded / decoded based on a data unit of a hierarchical structure having various sizes outside the conventional macroblock. Accordingly, the video coding apparatus 1400 according to the embodiment can variably set the generation method of the differential residual signal in consideration of the data unit of the hierarchical structure, thereby improving the compression efficiency of the image.

21 is a flowchart illustrating a video encoding method according to an embodiment.

Referring to FIGS. 14 and 21, in step 2110, the predictive encoding unit 1410 divides a picture into at least one maximum encoding unit, which is a maximum-size encoding unit. In step 2120, the maximum- And generates a residual signal of the prediction unit included in the coding unit based on the prediction unit for prediction of the unit and the coding unit.

In step 2130, the differential residual control information generator 1420 generates a differential residual control signal for controlling the generation of the differential residual signal of the residual signal included in the coding unit, based on at least one layer information of the coding unit, Information. As described above, at least one of the size of the encoding unit, the size of the prediction unit, the size of the conversion unit, the type of the prediction mode applied to the prediction unit, the type of the prediction unit included in the encoding unit, Can be used. The control information includes information on a data unit in which a differential residual signal is generated among an encoding unit, a prediction unit, and a conversion unit, size information of a data unit in which a differential residual signal is generated, Flag information indicating whether or not to use the signal, and information regarding a generation direction of the differential residual signal.

In step 2140, the differential residual signal generator 1430 generates a differential residual signal of the residual signal included in the coding unit based on the control information.

When a differential residual signal is generated according to an embodiment, a flag (enable_RDPCM_flag) is included in one of the VPS, SPS, PPS, and slice segments to indicate whether the differential residual signal is used and is transmitted to the decoding side. If the generation method of the control information related to the differential residual signal generation according to the embodiment is set in advance on the encoding side and the decoding side in advance, only the flag (enable_RDPCM_flag) information is transmitted (implicit mode). On the encoding side, control information used in generating the differential residual signal may be separately included in one of the VPS, SPS, PPS, and slice segments and transmitted to the decoding side (explicit mode).

22 is a block diagram showing a configuration of a video decoding apparatus according to an embodiment.

The video decoding apparatus 2200 according to the embodiment decodes video when the control information used in generating the differential residual signal is not included in the bitstream in addition to the flag (enable_RDPCM_flag) information according to the implicit mode.

22, the video decoding apparatus 2200 includes a receiving unit 2210, a residual reconstructing unit 2220, and a differential residual control information generating unit 2230.

The receiving unit 2210 obtains the size information of the maximum encoding unit, the layer information of the encoding unit obtained by dividing the maximum encoding unit, the layer information of the prediction unit, the layer information of the conversion unit, and the differential residual signal of the encoding unit from the bit stream.

The differential residual control information generator 2230 generates at least one of the coding units, the prediction units, and the conversion units used for the conversion of the coding units in the same manner as the differential residual control information generating unit 2230 of Fig. 14 And generates control information for generating a differential residual signal of the residual signal included in the encoding unit. That is, the differential residual control information generation unit 2230 determines, based on the layer information, how the differential residual signal is generated in the same way as on the encoding side.

The residual reconstructing unit 2220 reconstructs the residual signal of the encoding unit from the differential residual signal of the received encoding unit based on the control information. More specifically, when the differential residual signal is generated using the difference value of the residual signals of the pixels adjacent in the horizontal direction, the residual restoring unit 2220 restores the differential residual signal r (n) of the pixel located in the x- ' _{x , y} , the residual signal r _{x , y} of the pixel located in the x-th row and the y-th column can be restored as shown in Equation 3 below.

Similarly, when the differential residual signal is generated using difference values of the residual signals of pixels adjacent in the vertical direction, The differential residue inverse transforming unit 114 can restore the residual signal r _{x , y} of the pixel located in the x-th row and the y-th column as shown in the following Equation (4).

The residual of the decoding unit reconstructed by the residual reconstructing unit 2220 may be added to the prediction value generated by the predicting unit (not shown), and the encoding unit may be reconstructed.

23 is a block diagram showing a configuration of a video decoding apparatus according to another embodiment.

The video decoding apparatus 2300 according to another embodiment separately receives not only the flag (enable_RDPCM_flag) information according to the explicit mode but also the control information used in generating the differential residual signal, and outputs the differential residual signal And decodes the residual signal.

The receiving unit 2310 obtains the size information of the maximum encoding unit, the hierarchical information of the encoding unit obtained by dividing the maximum encoding unit, the hierarchical information of the prediction unit, the hierarchical information of the conversion unit, and the differential residual signal of the encoding unit from the bit stream. Also, the receiving unit 2310 acquires the control information generated based on at least one layer information of the encoding unit, the prediction unit, and the conversion unit and used for generation of the differential residual signal.

The residual reconstructing unit 2320 reconstructs the residual signal of the encoding unit from the differential residual signal of the received encoding unit based on the received control information, similar to the residual reconstructing unit 2220 of FIG. 22 described above. The video decoding apparatus 2200 according to the embodiment generates the control information from the layer information in the same manner as the encoding side without receiving the separate control information and uses the control information for reconstruction of the residual signal, The device 2300 operates similarly except that it separately receives control information from the bit stream and restores the residual signal based on the received control information.

24 is a flowchart illustrating a video decoding method according to an embodiment.

Referring to FIGS. 22 and 24, in step 2410, hierarchical information of a coding unit obtained by dividing a maximum coding unit, which is a maximum-size coding unit obtained by dividing a picture from a bit stream of the receiving unit 2210, The hierarchical information of the prediction unit, the hierarchical information of the conversion unit for the inverse transformation of the coding unit, and the differential residual signal of the coding unit are acquired.

In step 2420, the differential residual control information generating unit 2230 generates control information used for generating the differential residual signal based on at least one layer information among the encoding unit, the prediction unit, and the conversion unit.

In step 2430, the residual reconstruction unit 2220 reconstructs the residual signal of the coding unit from the differential residual signal of the coding unit based on the control information. As shown in Equations (3) and (4), the residual reconstructing unit 2220 reconstructs the residual signal from the pixel located at the boundary of the data unit in which the differential residual signal is generated among the coding unit, the prediction unit, The residual signal can be restored by summing up the residual residual signals.

25 is a flowchart illustrating a video decoding method according to another embodiment.

Referring to FIG. 23 and FIG. 25, in step 2510, the receiving unit 2310 receives hierarchical information of a coding unit obtained by dividing a maximum coding unit, which is a coding unit of the maximum size obtained by dividing a picture from a bitstream, The layer information of the conversion unit for inverse conversion of the encoding unit, and the differential residual signal of the encoding unit are obtained.

In step 2520, the receiving unit 2310 generates the control information used for generating the differential residual signal, based on at least one layer information of the encoding unit, the prediction unit, and the conversion unit, in addition to the layer information of the data units, / RTI >

In step 2530, the residual restoring unit 2320 restores the residual signal of the coding unit from the differential residual signal of the coding unit based on the control information. As shown in Equations (3) and (4), the residual reconstructing unit 2320 reconstructs the residual signal from the pixel located at the boundary of the data unit in which the differential residual signal is generated among the coding unit, the prediction unit, The residual signal can be restored by summing up the residual residual signals.

The present invention can also be embodied as computer-readable codes on a computer-readable recording medium. A computer-readable recording medium includes all kinds of recording apparatuses in which data that can be read by a computer system is stored. Examples of the computer-readable recording medium include ROM, RAM, CD-ROM, magnetic tape, floppy disk, optical data storage, and the like. The computer readable recording medium may also be distributed over a networked computer system and stored and executed in computer readable code in a distributed manner.

The present invention has been described with reference to the preferred embodiments. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims. The scope of the present invention is defined by the appended claims rather than by the foregoing description, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

Claims (21)

A video encoding method comprising:
Dividing the picture into at least one maximum encoding unit which is a maximum-size encoding unit;
Based on a coding unit obtained by hierarchically dividing the maximum coding unit according to a depth indicating the number of spatial division of the maximum coding unit and a prediction unit for prediction of the coding unit, Generating a signal;
Generates control information for generating a residual residual signal of a residual signal included in the encoding unit based on at least one layer information among the encoding units, the prediction units, and the conversion units used for conversion of the encoding units step; And
And generating a differential residual signal of a residual signal included in the coding unit based on the control information. The method according to claim 1,
The layer information
A size of the prediction unit, a size of the conversion unit, a type of a prediction mode applied to the prediction unit, and a tree structure type of the prediction unit or the conversion unit included in the encoding unit Wherein the video coding method comprises the steps of: The method according to claim 1,
The control information
Wherein the coding unit, the prediction unit, and the conversion unit include information on a data unit for generating the differential residual signal, size information of a data unit for which the differential residual signal is generated, The flag information indicating whether to use the residual signal of the differential residual signal, and information on the generation direction of the differential residual signal. The method according to claim 1,
And transmitting the control information in addition to a Video Parameter Set (VPS), a Sequence Parameter Set (SPS), a Picture Parameter Set (PPS), and a Network Adaptive Layer (NAL) of a slice. The method according to claim 1,
The step of generating the differential residual signal
Determining a data unit in which the differential residual signal is generated among the coding unit, the prediction unit, and the conversion unit based on the layer information; And
And calculating a difference value of residual signals of adjacent pixels included in the determined data unit in a predetermined direction to obtain the differential residual signal. 6. The method of claim 5,
The step of determining the data unit
Wherein a data unit within a predetermined size range of the encoding unit, the prediction unit, and the conversion unit is determined as a data unit in which the differential residual signal is generated. 6. The method of claim 5,
Wherein the predetermined direction is preset or determined based on an intra prediction direction of pixels included in the data unit. A video encoding apparatus comprising:
A coding unit in which the maximum coding unit is hierarchically divided according to a depth indicating the number of spatial division of the maximum coding unit and prediction of the coding unit A prediction encoding unit for generating a residual signal of a prediction unit included in the encoding unit based on the prediction unit for the prediction unit;
Generates control information for generating a residual residual signal of a residual signal included in the encoding unit based on at least one layer information among the encoding units, the prediction units, and the conversion units used for conversion of the encoding units A differential residual control information generation unit; And
And a differential residual signal generator for generating a differential residual signal of a residual signal included in the coding unit based on the control information. A video decoding method comprising:
Layer information of a coding unit obtained by dividing a maximum coding unit, which is a coding unit of a maximum size obtained by dividing a picture, based on the depth, layer information of a prediction unit for prediction of the coding unit, Obtaining hierarchical information of a conversion unit and a differential residual signal of the coding unit;
Obtaining control information used for generating the differential residual signal based on hierarchical information of at least one of the encoding unit, the prediction unit, and the conversion unit; And
And restoring the residual signal of the coding unit from the differential residual signal of the coding unit based on the control information. 10. The method of claim 9,
The layer information
A size of the prediction unit, a size of the conversion unit, a type of a prediction mode applied to the prediction unit, and a tree structure type of the prediction unit or the conversion unit included in the encoding unit The video decoding method comprising the steps of: 10. The method of claim 9,
The control information
Wherein the coding unit, the prediction unit, and the conversion unit include information on a data unit for generating the differential residual signal, size information of a data unit for which the differential residual signal is generated, The flag information indicating whether to use the residual signal of the differential residual signal, and the information about the generation direction of the differential residual signal. 10. The method of claim 9,
The step of restoring the residual signal
Determining a data unit in which the differential residual signal is generated among the coding unit, the prediction unit, and the conversion unit based on the layer information; And
And obtaining the residual signal by summing a difference residual signal of pixels from a pixel located at a boundary of the determined data unit to a pixel where a residual signal is calculated. 13. The method of claim 12,
The step of determining the data unit
Wherein a data unit within a predetermined size range of the encoding unit, the prediction unit, and the conversion unit is determined as a data unit in which the differential residual signal is generated. 13. The method of claim 12,
Wherein the predetermined direction is predetermined or determined based on an intra prediction direction of pixels included in the data unit. A video decoding method comprising:
Layer information of a coding unit obtained by dividing a maximum coding unit, which is a coding unit of a maximum size obtained by dividing a picture, based on the depth, layer information of a prediction unit for prediction of the coding unit, Obtaining hierarchical information of a conversion unit and a differential residual signal of the encoding unit;
Obtaining control information, which is generated from the bitstream based on at least one layer information among the encoding unit, the prediction unit, and the conversion unit, and used for generating the differential residual signal; And
And restoring the residual signal of the coding unit from the differential residual signal of the coding unit based on the control information. 16. The method of claim 15,
Wherein the control information is obtained from one of a Video Parameter Set (VPS), a Sequence Parameter Set (SPS), a Picture Parameter Set (PPS), and a Network Adaptive Layer (NAL) of a slice. A video decoding apparatus comprising:
Layer information of a coding unit obtained by dividing a maximum coding unit, which is a coding unit of a maximum size obtained by dividing a picture, based on the depth, layer information of a prediction unit for prediction of the coding unit, A receiving unit for acquiring hierarchical information of a conversion unit and a differential residual signal of the encoding unit;
A differential residual control information generation unit for generating control information used for generating the differential residual signal based on at least one layer information among the coding unit, the prediction unit and the conversion unit; And
And a residual restoring unit for restoring the residual signal of the coding unit from the differential residual signal of the coding unit based on the control information. A video decoding apparatus comprising:
Layer information of a coding unit obtained by dividing a maximum coding unit, which is a coding unit of a maximum size obtained by dividing a picture, based on the depth, layer information of a prediction unit for prediction of the coding unit, The control information used for generating the differential residual signal is generated based on the hierarchical information of the conversion unit, the differential residual signal of the coding unit, and hierarchical information of at least one of the coding unit, the prediction unit and the conversion unit, ; And
And a residual restoring unit for restoring the residual signal of the coding unit from the differential residual signal of the coding unit based on the control information. 8. A computer-readable recording medium on which a program for implementing the method of any one of claims 1 to 7 is recorded. A computer-readable recording medium on which a program for implementing the method of any one of claims 9 to 14 is recorded. 17. A computer-readable recording medium on which a program for implementing the method of any one of claims 15 to 16 is recorded.

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