KR19990058283A - Method and apparatus for mode signal encoding for use in binary shape coders - Google Patents

Abstract

The present invention relates to a method for encoding mode signals of a target block of M × N pixels having a binary value '0' or '255'. If the target block is not determined to be either "all_0" or "all_255", either frame-based coding or field-based coding is selected to generate a coding mode signal, where the basic mode of the target block is " based on all_0 "," all_255 "and / or the coding mode signal, the frame-based coding apparatus indicates that the target block is encoded in units of M × N pixels, and the field-based coding indicates the target block. This is encoded in units of M / 2 x N pixels. When the frame based coding is selected, a frame mode is generated. In contrast, when the field based coding is selected, the frame is divided into upper and lower fields to obtain an upper mode for the upper field and a changed lower mode for the lower field, wherein the lower mode is The upper mode and the changed lower mode are added to become the field mode by being changed by the upper mode.

Description

Method and apparatus for mode signal encoding for use in binary shape coders

The present invention relates to a method and apparatus for encoding mode signals of a binary shape signal, in particular suitable for encoding mode signals using a correlation between two fields in a parallel shape coder. A method and apparatus for mode signal encoding are provided.

In digital broadcast receiving systems such as video telephony, teleconferencing and high definition television systems, each video frame signal because the video line signal in the video frame signal includes a sequence of digital data referred to as pixel values. A large amount of digital data is required to define this. However, the available frequency bandwidth of a typical transmission channel is limited, so that in order to transmit large amounts of digital data to low bit rate video signal encoders, particularly used in video telephony and teleconferencing systems, It is essential to compress or reduce the volume of data using various data compression techniques.

In a low bit rate encoding system, one of several techniques for encoding video signals is a technique called object-oriented analysis-synthesis coding technique, where the input video image is divided into objects and the motion of each object , Three sets of parameters for defining the contour and the pixel data are each processed via different encoding channels.

One embodiment of such an object-oriented analysis-synthesis coding scheme is referred to as MPEG (Video Expert Group) 4 (MPEG-4), which provides low bit rate communication and interactive multimedia (e.g. gaming, interactive). Are designed to provide audio-video coding standards to allow content-based interactivity, improved coding efficiency and / or universal accessibility in applications such as TVs and surveillance equipment. .

According to MPEG-4, the input video image is divided into a number of video object planes (VOP's), which correspond to entities that are bitstreams that are accessible and manageable by the user. The VOP is referred to as an object and is represented by a bounding rectangle, the smallest of the rectangles whose width and height are integer multiples of the 16 pixels (macroblock size) that surrounds the object, so that the encoder processes the input video image in units of VOP. can do.

The VOP described in MPEG-4 includes shape information and color information consisting of luminance and chrominance data, wherein the shape information represented by binary shape signals is represented by an alpha plane ( an alpha plane). The alpha plane is divided into a number of binary alpha blocks (BABs) each having 16 x 16 binary pixels. Each binary pixel is classified as either a background pixel or an object pixel and is used to assign an object pixel within an object to have a different binary pixel value, for example, a value of 255, while a background located outside the object in the alpha plane. The pixel is used to be assigned to have a binary pixel value, for example a value of zero.

Each binary pixel in BAB is encoded using a conventional bitmap based shape coding method, such as a context-based arithmetic encoding (CAE) principle. For example, in intra mode, all binary pixels of BAB are encoded using intra CAE principle to generate intra coded BAB, but in intra CAE principle the content value for each binary pixel of BAB. Is computed using a predetermined number of binary pixel values, e.g., 10 binary pixels surrounding each of said binary pixels in BAB.

On the other hand, in inter mode, all binary pixels of the current BAB are encoded using the inter CAE principle to generate an inter-encoded BAB, where the content value of each binary pixel of the current BAB within the inter CAE principle Is a predetermined number of binary pixel values, for example four binary pixels surrounding each binary pixel in the current BAB, and a preset number of binary values, e.g., five binary pixels in the boundary motion compensated BAB. (See MPEG-4 Video Verification Model Version 7.0, International Organization for Standardization, Coding of Moving Pictures And Associated Audio Information, ISO / IEC JTC1 / SC29 / WG11 MPEG97 / N1642, Bristol, April 1997, pp 28-30).

For example, if all the binary pixels in a BAB are object pixels, instead of encoding the binary pixel values of the object pixels to generate encoded binary pixel values to be transmitted, indicating that all the binary pixels in the BAB are object pixels. It is desirable to encode the mode signal. By employing the above method, the coding efficiency can be increased by transmitting a corresponding encoding mode signal such as binary shape information for BAB.

Referring to Table 1, there are seven modes of binary alpha information of BAB according to the conventional mode coding principle, where the motion vector difference (MVD) for the shape of BAB is related to the motion vector (MV) for the shape and the shape. Is the difference between motion vector predictors (MVPs), and MVP is determined using conventional motion judgment principles (MPEG-4 Video Verfication Model Version 7.0, International Organization for Standardization, Coding of Moving Pictures And Associated Audio Information, ISO / IEC JTC / SC29 / WG11 MPEG97 / N1642, Bristol, April 1997, pp 20-23).

mode coding condition One MVD == 0 && no_update 2 MVD! = 0 && no_update 3 MVD == 0 && inter_CAE 4 MVD! = 0 && inter_CAE 5 intra_CAE 6 all_0 7 all_255

In Table 1, mode 1 indicates that the shape's motion vector difference (MVP) for BAB is defined as 0 and that all binary pixels in BAB do not need to be encoded, and mode 2 does not define MVD as 0 and in BAB Mode 3 indicates that all binary pixels do not need to be encoded, mode 3 indicates that MVD is defined as 0 and all binary pixels in BAB are encoded by the inter CAE principle, and mode 4 indicates that MVD is not defined as 0 and all binary in BAB The pixels indicate that they have been encoded by the inter CAE principle, mode 5 indicates that all binary pixels in the BAB have been encoded by the intra CAE principle, mode 6 indicates that all binary pixels in the BAB are defined as background pixels, and mode 7 indicates that in the BAB Indicates that all binary pixels are defined as object pixels.

Conventional binary shape encoding methods employing the conventional mode coding method described above are basic progressive coding methods. That is, in the conventional binary shape encoding method, a parallel coding technique performed using the field-based motion determination method is not used.

Therefore, the above-described conventional method has a problem that even when the spatial and / or temporal correlation between the frames is smaller than the correlation of the fields, the parallel coding technique is not employed, resulting in a poor coding efficiency.

It is a first object of the present invention to provide a method and apparatus for efficiently coding mode signals by appropriately performing progressive coding or convolutional coding.

It is a second object of the present invention to provide a method and apparatus that can efficiently code mode signals by changing a lower mode of a lower field to an upper mode of an upper field in a perturbed coding.

According to the present invention, an M × N pixel of a binary shape signal comprising a plurality of pictures when a target block representing one of the blocks of the current picture to be encoded and M and N are each positive positive integers, respectively. A method is provided for encoding mode signals of a target block to be encoded by either frame encoding to be encoded in units of data or field based coding to be encoded in units of M / 2 × N pixels, the method comprising: (a ) When the individual reference blocks have M × N pixels and all the pixels of the first and second reference blocks are first and second binary values, respectively, the error of the target block for the first reference block is greater than a preset threshold. Generating a first indication signal if not large and a second indication signal if the error of the target block for the second reference block is not greater than the predetermined threshold. Generating a; (b) if none of the first and second indication signals have been generated in step (a), coding indicating that the target block is encoded using either the frame-based coding or the field-based coding Selecting one of the frame based coding or the field based coding to generate a mode signal; (c) generating a basic mode of the target block based on the first and second display signals and the coding mode signal; (d) if the frame-based coding is selected in step (b), the frame-based coding generates the target block to generate a frame mode and frame coded data indicating a coding condition of the frame coded data. Coding; (e) if the field-based coding is selected in step (b), coding the target block with the field-based coding to generate field mode and field coded data; And (f) combining the basic mode and the frame mode or the field mode to generate a mode signal for transmitting the target block.

The above objects and features of the present invention will become apparent from the following description of the preferred embodiments associated with the accompanying drawings.

1 is an apparatus diagram for coding modes of shape information based on a binary alpha block (BAB) according to a preferred embodiment of the present invention;

FIG. 2 is a detailed block diagram of the frame coding circuit shown in FIG. 1;

3 is a detailed block diagram of the field coding circuit shown in FIG.

<Explanation of symbols for main parts of drawing>

10: frame detector 20: mode selector

27: frame divider 30: frame coding unit

47: frame mode coding unit 50: upper field coding unit

67: upper mode coding unit 70: lower field coding unit

87: lower mode coding unit

Referring to FIG. 1, an apparatus for coding modes of shape information in units of a binary alpg block (BAB) is shown according to a preferred embodiment of the present invention, wherein the shape information displayed in the binary shape signals is It is referred to as the alpha plane. The alpha plane is divided into a plurality of binary alpha blocks, and binary alpha blocks each having 16 x 16 binary pixels are provided to the frame detection circuit 10 as shape information.

The frame detection circuit 10 checks whether the coding mode of each BAB is "all_0" or "all_255". In particular, the BAB is preferably divided into sixteen subblocks of 4 × 4 pixels. If all errors between all subblocks of BAB and all_0 subblock are less than or equal to the preset threshold, all binary pixels of BAB are changed to background pixels with pixel value '0', so that BAB is " all_0 " An indication signal S ₁ = 'all_0' is provided to the mode multiplexer (MUX) 90, which is defined as, where all_0 subblocks are all subblocks with binary pixel values of '0'. Also, if all errors between all subblocks of BAB and all_255 are less than or equal to the preset threshold, all binary pixels of BAB are changed to object pixels with pixel value '255', so that BAB is " all_255 " An indication signal S ₁ = 'all_255' is provided to the mode MUX 90, which is defined as, wherein all_255 subblocks are all subblocks having binary pixel values of '255'.

When the coding mode of BAB is neither "all_0" or "all_255", the alpha plane of BAB is provided to the mode selection circuit 20 and the switch 25. The mode selection circuit 20 determines that BAB is encoded in one of frame units or field units, and generates a coding mode signal S ₂ indicating that BAB is encoded in one of frame units or field units, and this coding mode signal S ₂ To switch 250 and mode MUX 90. Mode MUX 90 generates a basic mode signal for BAB based on display signal S ₁ and coding mode signal S ₂ .

Referring to Table 2, four typical basic mode signals generated in mode MUX 90 are illustrated.

base mode base mode signal all_0 0 all_255 One field mode 10 frame mode 11

At the switch 25, the BAB is switched to either the frame coding circuit 30 or the frame divider 270 based on the coding mode signal S _{2. In} particular, in the case where the BAB is encoded frame by frame, the BAB is represented as BAB frame data. The frame coding circuit 30 is provided, and in other cases, the BAB is provided to the frame divider 27.

Referring to FIG. 2, a detailed block diagram of the frame coding circuit shown in FIG. 1 is shown, where BAB frame data is the current BAB, frame no_update circuit 32, motion estimation and motion compensation (ME & MC) circuit 33 And frame MUX 35 in frame reconstruction unit 44.

The ME & MC circuit 33 determines the motion vector predictor (MVP) of the current BAB based on the candidate MVP retrieved from the memory 34 in the frame reconstruction unit 44, and determines the motion vector ( MV) and motion vector difference (MVD), and perform motion compensation according to MV to generate a boundary motion compensated (boundary MC) block, and perform MVD and boundary MC blocks on MVD coding circuit 36 and frame, respectively. provided to the no_update circuit 32, where MVD represents a displacement between MV and MVP, and the boundary MC block represents a motion compensated BAB (MC BAB) obtained by replacing each binary pixel of the previous BAB corresponding to MVP with MV. And one pixel width boundary around the MV BAB (MPEG-4 Video Verification Model Version 7.0, International Organization for Standardization, Coding of Moving Pictures And Associated Information, ISO / IEC JCT1 / SC29 / WG11 MPEG97 / N1642, Bristol , April 1997, pp 2 0-23).

The MVD coding circuit 36 generates an MVD signal S ₃ indicating whether or not the MVD is '0', provides the MVD signal S ₃ to the mode determining circuit 43, and when the MVD is not '0', The MVD coding circuit 36 encodes the MVD of the current BAB, and interleaves this encoded MVD data itself via the line L36 in the interbit arithmetic circuit 40 and the MUX 90 in the context_based arithmetic encoding unit (CAE unit) 45. To provide.

In the meantime, the frame no_update circuit 32 determines whether the current BAB is equal to the MC BAB, and provides the mode determining circuit 43 with a no_update signal S ₄ indicating whether the current BAB should be encoded. Initially, frame no_update circuit 32 divides the current BAB into 16 current subblocks and divides MC BAB into 16 MC subblocks, where the current subblocks and the MC subblocks are each 4 ×. The MC BAB field with four pixels is obtained by removing the one pixel wide border around the boundary MC BAB.

Frame no_update circuit 52 determines whether each error between each current BAB subblock and the BAB subblock corresponding to the MC subblock is less than or equal to a predetermined threshold. At this time, if all errors are less than or equal to the preset threshold, it is preferable that the current BAB does not need to be encoded so that the signal S ₄ represents no_update.

In contrast, if at least one of the errors between the BAB blocks and the BAB subblocks corresponding to the MC subblocks is greater than a predetermined threshold, that is, the current BAB should be coded as described below. In the case, the frame no_update circuit 32 provides the current BAB to the intra context_based arithmetic encoding (intra CAE) circuit 37 and the inter CAE circuit 39 in the CAE unit 45, and the boundary MC BAB to the inter CAE circuit ( 39).

Intra CAE circuit 37 encodes all binary pixels of the current BAB based on three adjacent reconstructed fields retrieved from frame MUX 35 in reconstruction unit 44 via line L35 using conventional intra CAE principles. Wherein each reconstructed BAB adjacent to the current BAB in the upper left, upper or left direction comprises 16 × 16 reconstructed pixels. In the conventional intra CAE principle, the intra content value for each binary pixel of the current BAB is computed using a predetermined number of binary pixel values, i.e., ten candidate pixels surrounding each binary pixel, wherein the candidate binary The pixels are computed using all reconstructed pixels in three adjacent reconstructed BABs and one or more intra encoded current pixels already encoded by the intra CAE principle, if any, wherein each binary pixel is based on an intra content value. To be an intra-encoded pixel for each of the binary pixels. All intra encoded pixels are provided to intra bit arithmetic circuit 38 and selector 42 as intra CAE data.

The intra bit arithmetic block 38 calculates the number of bits required to represent intra CAE data and provides the comparator 41 with the number of bits of the intra CAE data.

In the meantime, the inter CAE circuit 39 encodes all binary pixels of the current BAB and the boundary MC BAB based on the adjacent reconstructed BAB retrieved through the line L35 using the inter CAE principle. In the inter CAE principle, the inter content value of each binary pixel in the current BAB is a predetermined number of binary pixel values, e.g. four reconstructed binary pixels and binary values surrounding each of the binary pixels in the current BAB. Computed using five boundary MC binary pixels in a predetermined number, e.g., boundary motion compensated BAB, wherein each binary pixel is encoded based on an inter content value to generate an inter-encoded pixel for each binary pixel. do. All inter encoded pixels are provided to inter bit arithmetic circuit 40 and selector 42 as inter CAE data, respectively.

The inter bit arithmetic circuit 40 calculates the number of bits necessary to represent both inter CAE data and encoded MVD data, and provides this to the comparator 41.

In the comparator 41, if the number of bits of the intra CAE data is smaller than the number of bits of the inter CAE data and the encoded MVD data, the intra / inter signal S ₅ representing the intra CAE data is selected by the selector 42 and the mode determining circuit 43. In other cases, an intra / inter signal S ₅ representing inter CAE data and encoded MVD data is provided to the selector 42 and the mode determining circuit 43.

In response to the intra / inter signal S ₅ , the selector 42 selects MVD data encoded with either intra CAE data or inter CAE data to provide the selected result to the MUX 95.

In the meantime, the mode determination circuit 43 determines the frame coding mode of the current BAB based on the signals S ₃ , S ₄ , and shows the frame coding mode in the frame MUX 35 in the frame reconstruction unit 440 and in FIG. 1. To the frame mode coding circuit 70.

In response to the frame coding mode output from the mode decision circuit 43, the frame MUX 35 reconstructs the current BAB to generate a reconstructed BAB. In other words, the frame MUX 35 replaces the MC BAB with the BAB reconstructed based on the frame coding mode among the current BAB itself or the boundary MC BAB input from the MC & ME circuit 33. The reconstructed BAB is provided from the frame MUX 35 to the memory 34, the intra CAE circuit 37 and the inter CAE circuit 39 via the line L35 to process the next BAB frame data.

Referring back to FIG. 1, frame mode coding circuit 47 generates a frame mode signal for the current BAB based on conventional statistical coding techniques to provide frame mode signal to mode MUX 90.

frame coding mode frame mode signal MVD == 0 && no_update 0 MVD! = 0 && no_update 110 MVD == 0 && inter_CAE 10 MVD! = 0 && inter_CAE 1110 intra_CAE 1111

Referring to Table 3, according to the frame mode signals based on signals S ₃ , S ₄ , and S ₅ , five typical frame mode signals for frame BAB are shown, where the motion vector difference (MVD) for the shape of frame BAB is shown. ) Is the difference between the motion vector (MV) for the shape and the motion vector predictor (MVP) for the shape, and MVP is determined using conventional motion estimation principles.

In contrast, when BAB is provided from the switch 25 to the frame divider 27 for encoding field-by-field responsive to the coding mode signal S ₂ , the frame divider 27 includes the BAB as all the odd rows of the BAB. The upper field BAB and the lower field BAB including all even rows of the BAB are divided, and the upper and lower field BAB are provided to the upper and lower field coding circuits 50 and 70 as field BAB data, respectively. If the BAB has 16 x 16 pixels, each of the upper and lower field BAB preferably has 8 x 16 pixels. Since the upper field coding circuit 50 is actually the same as the lower field coding circuit 70, the display field coding circuit is described as follows.

Referring to FIG. 3, a detailed block diagram of the top / bottom field coding circuit shown in FIG. 1 is shown, with field BAB data being provided to the field detection circuit 51 as the current field BAB. Since the field coding circuit is similar to the frame coding circuit, the field coding circuit is briefly described as follows.

The field detection circuit 51 checks the coding mode of each current field BAB in units of fields if the coding mode is one of "all_0" and "all_255". If one of the current field BAB coding mode of "all_0" or "all_255", the indication signal S ₆ indicating that the current field is defined as either "all_0" or "all_255" is provided to the mode decision circuit 63. If the coding mode of the current field BAB is neither "all_0" nor "all_255", the current field BAB is the field no_update circuit 52, the ME & MC circuit 53, and the field MUX 55 in the field reconstruction unit 64. Is provided.

The ME & MC circuit 53 determines the motion vector predictor (MVP) of the current field BAB based on the candidate MVP retrieved from the memory 64 in the field reconstruction unit 64 according to the conventional MPEG-4 principle, where Each candidate MVP is preferably selected from the reconstructed lower field BAB of the reconstructed frame BAB in memory 34. Typically, the frame reconstruction unit 44 of the upper field coding circuit 50, the lower field coding circuit 70 and the frame coding circuit 30 shown in FIG. 2 has a memory 34. After calculating the MV and MVD of the current field BAB, the ME & MC circuit 53 provides the MVD and boundary MC fields to the MVD coding circuit 56 and the field no_update circuit 52, respectively, where MVD is the MV and MVP. The displacement MC field block represents both the MC field BAB and the boundary of one pixel width around the MC field BAB. The MC field BAB for the upper and lower field BAB is obtained by replacing each binary pixel of the upper or lower field BAB of the previous BAB corresponding to the MVP with MV.

The MVD coding circuit 56, which is actually identical to the MVD coding circuit 36 of the frame coding circuit, provides the mode determining circuit 63, if any, with an MVD signal S ₇ indicating whether the MVD is '0', and the encoded MVD data itself. The MVD of the current field BAB is encoded and provided to the inter-bit arithmetic circuit 60 and the data MUX 90 in the CAE unit 65 via the line L56 to provide.

In the meantime, the field no_update circuit 52 provides the no_update signal S ₈ to the mode determining circuit 63, where the no_update signal S ₈ indicates whether the current field BAB is equal to the MC field BAB and thus the current field BAB is encoded. Should be. In the case where the current field BAB is equal to the MC field BAB, it is preferable that the current BAB is not encoded so that the signal S ₈ indicates no_update. On the contrary, if the current BAB should be encoded as described below, the field no_update circuit 52 replaces the current field BAB and the boundary MC field BAB with "frame" to "field" except that the frame coding circuit ( To the CAE unit 65 in a similar manner as described above with respect to 30).

Since the CAE unit 65 of the upper / lower field coding units 50 and 70 is actually the same as the CAE unit 45 of the frame coding circuit 30 shown in FIG. 2, the upper / lower field coding circuit 50 is likewise. The CAE unit 65 of 70 denotes an intra CAE circuit 57, an intra bit arithmetic circuit 58, an inter CAE circuit 59, an inter bit arithmetic circuit 60, a comparator 61 and a selector 62. Include. From the comparator 61, an intra / inter signal S ₉ indicating whether intra CAE data for the current field BAB is preferably inter CAE data is provided to the selector 62 and the mode determining circuit 63, and the intra / inter In response to the signal S ₉ , the selector 62 selects one of the intra CAE data or the inter CAE data, thereby providing the selected result to the data MUX 95.

In the meantime, the mode determination circuit 63 determines the field coding mode of the current field BAB based on the signals S ₆ , S ₇ , S ₈ , S ₉ , and sets the field coding mode in the frame MUX 55 in the reconstruction unit 64. To provide. Further, the field coding mode is provided from the upper field coding circuit 50 to the upper mode coding circuit 67 or from the lower field coding circuit 70 to the lower mode coding circuit 87 as shown in FIG.

The field coding mode has nine field coding modes including two or more specific modes in addition to the usual seven modes in MPEG-4, namely "coded with upper field content" and "not coded with prediction". Is selected to provide the field coding mode to the lower MUX 55 in the reconstruction unit 64 and the lower mode generator 83 in the lower mode coding circuit 80 shown in FIG.

In response to the field coding mode output from the mode determination circuit 63, the frame MUX 55 reconstructs the current field BAB. In other words, in response to the field coding mode, frame MUX 55 enters any " all_0 " field BAB, " all_255 " field BAB, current field BAB itself and ME & MC circuit 53 input from field detection circuit 51. ) Replaces the input MC field BAB with the reconstructed field BAB for the current field BAB. The reconstructed field BAB is provided from the field MUX 55 to the memory 34, the intra CAE circuit 57 and the inter CAE circuit 59 via the line L55 to process the next field BAB data.

Referring back to FIG. 1, the top mode coding circuit 67 generates the top mode signal for the current top field BAB based on conventional statistical coding techniques to provide the top mode signal to the bottom mode coding circuit 87. do.

top mode top mode signal MVD == 0 && no_update (T1) 11110 MVD! = 0 && no_update (T2) 110 MVD == 0 && inter_CAE (T3) 10 MVD! = 0 && inter_CAE (T4) 0 intra_CAE (T5) 1110 all_0 (T6) 111110 all_255 (T7) 111111

Referring to Table 4, _seven typical top mode signals for the top field BAB are shown according to the top coding mode based on signals S ₆ , S ₇ , S ₈ , S ₉ , where T1 is the motion of the shape for BAB. First binary mode indicating that the vector difference MVD is defined as 0 and all binary pixels in BAB need not be encoded, and so on.

The lower mode coding circuit 87 generates a modified lower mode signal for the current lower field BAB based on a conventional statistical coding technique, wherein the changed lower mode signal is determined in dependence on the upper mode signal, and the upper mode signal is changed to the modified lower mode. In addition to the mode signal, a mode signal added as a field mode signal is provided to the mode MUX 90.

Referring to Table 4, forty-seven typical modified lower mode signals for the lower field BAB modified by the seven mode signals are illustrated, where B1 is equal to the motion vector difference (MVD) of the shape for BAB defined as zero. All binary pixels in the BAB need not be encoded, and the like. When i is 1 to 7, Bi is the bottom field, just as Ti is the top field. Since "all_0" for the frame BAB has already been checked in the frame detection circuit 10, there is no "all_0" in the lower mode for the sixth upper mode T6.

Referring back to FIG. 1, after generating the basic mode signal based on the display signal S ₁ and the coding mode signal S ₂ as described above, the mode MUX 90 provides the basic mode to provide the mode signal to the data MUX 95. Multiply frame and field mode signals based on the signal.

The data MUX 95 multiplies the frame encoded data and the lower field encoded data into the upper field encoded data based on the mode signal to transmit the multiplied data to the transmitter (not shown).

While the invention has been described with respect to particular implementations, those skilled in the art will recognize that various changes and modifications can be made without departing from the spirit and scope of the invention as defined in the following appended claims.

As described above, according to the present invention, the coding efficiency for the mode signals can be improved by adaptively performing progressive coding or convolutional coding, and also, in convolutional coding, the lower mode of the lower field is selected from the upper part of the upper field. By changing to mode to perform mode coding, coding efficiency for mode signals can be enhanced.

Claims (14)

When M and N are each positive positive integers and a target block representing one of the blocks of the current picture to be encoded, the binary block of the binary shape signal containing a plurality of pictures is to be encoded in units of M × N pixels. A method for encoding mode signals of a target block to be encoded by either frame-based coding or field-based coding to be encoded in units of M / 2 × N pixels, (a) When the individual reference blocks have M × N pixels and all the pixels of the first and second reference blocks are first and second binary values, respectively, the threshold of an error of the target block for the first reference block is preset. Generating a first indication signal if it is not greater than, generating a second indication signal if the error of the target block for the second reference block is not greater than the predetermined threshold; (b) if none of the first and second indication signals have been generated in step (a), coding indicating that the target block is encoded using either the frame-based coding or the field-based coding Selecting one of the frame based coding or the field based coding to generate a mode signal, (c) generating a basic mode of the target block based on the first and second display signals and the coding mode signal; (d) if the frame-based coding is selected in step (b), the frame-based coding generates the target block to generate a frame mode and frame coded data indicating a coding condition of the frame coded data. Coding, (e) if the field-based coding is selected in step (b), coding the target block with the field-based coding to generate field mode and field coded data; (f) combining the basic mode and the frame mode or the field mode to generate a mode signal for transmitting the target block; Mode signal encoding method comprising a. The method of claim 1, wherein step (e) (e1) the target block into an upper field including all odd rows of the target block to have M / 2 × N pixels and a lower field containing all even rows of the target block to have M / 2 × N pixels Dividing step, (e2) coding the upper field to generate an upper mode and upper field coded data indicating a coding condition of the upper field coded data; (e3) coding the lower field to generate a lower mode and lower field coded data representing a coding condition of the lower field coded data; (e4) changing the lower mode based on the upper mode to generate a changed field mode; (e5) adding the upper mode to the modified lower mode to generate a field mode Mode signal encoding method comprising a. The method of claim 1, wherein step (d) (d1) generating motion vector information including a motion vector and a motion compensated block having the most similar block of the target block by performing motion estimation and compensation based on one or more previous pictures of the current picture; Wow, (d2) calculating a motion compensation error (MCE) between the target block and the most similar block and a motion vector difference (MVD) between the motion vector and a predictor thereof; (d3) generating an MVD signal indicating whether the MVD is 0; (d4) encoding the MVD to generate MVD data when the MVD is not 0; (d5) setting a no_update signal indicating whether the MCE is smaller than the preset threshold; (d6) when the MCE is smaller than the preset threshold, the intra coded data generated by encoding pixels of the target block based on preset pixels of the current picture and the motion compensated block with the current picture. Generating inter coded data provided by encoding the pixels of the target block based on the included current pixels; (d7) generating an intra / inter signal when the intra coded data or the inter coded data is selected; (d8) determining the frame mode based on the MVD signal, the no_update signal and / or the intra / inter signal. Mode signal encoding method comprising a. The method of claim 3, wherein step (d7), (d71) calculating the number of bits of the intra coded data and the number of bits of the inter coded data; (d72) comparing the number of bits with each other to select a small number of bits; (d73) in response to the small number of bits, generating an intra / inter signal indicating whether the number of bits of the intra coded data is less than the number of bits of the inter coded data; (d74) in response to the intra / inter signal, generating one of the intra coded data or the inter coded data as the frame coded data Mode signal encoding method comprising a. The method of claim 2, wherein steps (e2) and (e3), (e21) When the individual reference blocks have M / 2 × N pixels and all the pixels of the first and second reference fields are the first and second binary values, respectively, the upper / lower field of the upper / lower field for the first reference block. Generating a first field indication signal if the error is not greater than a preset threshold, and if the error of the upper / lower field for the second reference field is not greater than the preset threshold, Generating a two-field display signal; (e22) when the first and second field indication signals are not generated in step (e21), by performing motion estimation and compensation on the upper / lower field based on one or more previous pictures of the current picture, a motion vector Generating motion vector information comprising a motion compensated field having the most similar field of the upper / lower field; (e23) calculating a motion compensation error (MCE) between the upper / lower field and the most similar field and a motion vector difference (MVD) between the motion vector and its predictor, (e24) generating a field MVD signal indicating whether the MVD is 0; (e25) encoding the MVD to generate MVD data when the MVD is not 0; (e26) setting a field no_update signal indicating whether the MCE is smaller than the preset threshold; (e27) when the MCE is not smaller than the preset threshold, the field intra coded data and the current picture generated by encoding the pixels of the upper / lower field based on predetermined pixels of the current picture. Generating field inter coded data provided by encoding the pixels of the upper / lower field based on current pixels included in the motion compensated field; (e28) generating a field intra / inter signal when one of the field intra coded data or the field inter coded data is selected; (e29) determining the field mode based on the first / second field indication signal, the field MVD signal, the field no_update signal and / or the field intra / inter signal. Mode signal encoding method comprising a. The method of claim 5, wherein step (e28) (e281) calculating the number of bits of the field intra coded data and the number of bits of the field inter coded data; (e282) comparing the number of bits with each other to select a small number of bits; (e283) generating a field intra / inter signal representing the field intra coded data and the field inter coded data in response to the small number of bits; (e284) in response to the field intra / inter signal, providing one of the field intra coded data or the field inter coded data as the field coded data Mode signal encoding method comprising a. 7. The method of claim 5 or 6 wherein the intra coded data is provided by an intra content based arithmetic encoding (CAE) method and the inter coded data is provided by an inter CAE method. When M and N are each positive positive integers and a target block representing one of the blocks of the current picture to be encoded, the binary block of the binary shape signal containing a plurality of pictures is to be encoded in units of M × N pixels. An apparatus for encoding mode signals of a target block encoded by either frame-based coding or field-based coding to be encoded in units of M / 2 × N pixels, When the individual reference blocks have M × N pixels and all the pixels of the first and second reference blocks are first and second binary values, respectively, the error of the target block for the first reference block is greater than a predetermined threshold. Block detecting means for generating a first display signal if not, and for generating a second display signal if the error of the target block with respect to the second reference block is not greater than the preset threshold; Mode selection for selecting one of the frame-based coding or the field-based coding to generate a coding mode signal indicating that the target block is encoded using either the frame-based coding or the field-based coding Sudan, Frame-based coding means for coding the target block by the frame-based coding to generate a frame-mode and frame-coded data indicating a coding condition of frame-coded data in response to the coding mode signal; Field-based coding means for coding the target block by the field-based coding to generate a field mode and field coded data in response to the coding mode signal; A multiplexer for combining the basic mode and the frame mode or the field mode to generate a mode signal for transmitting the target block Mode signal encoding apparatus comprising a. The method of claim 8, wherein the frame-based coding means, For dividing the target block into an upper field containing all radix rows of the target block to have M / 2 x N pixels and a lower field containing all even rows of the target block to have M / 2 x N pixels Block divider, A top field encoder for coding the top field to generate a top mode and top field coded data indicating a coding condition of the top field coded data; A lower field encoder for coding the lower field to generate a lower mode and lower field coded data indicating a coding condition of the lower field coded data; Means for changing the lower mode based on the upper mode to generate a modified lower mode; Means for adding the upper mode to the modified lower mode to generate a field mode Mode signal encoding apparatus comprising a. The method of claim 8, wherein the frame-based coding means, Means for generating motion vector information comprising a motion vector and a motion compensated block having the most similar block of the target block by motion estimation and compensating the target block based on one or more previous pictures of the current picture; , Means for calculating a motion compensation error (MCE) between the target block and the most similar block and a motion vector difference (MVD) between the motion vector and its predictor; Means for generating an MVD signal indicating whether the MVD is zero; Means for encoding the MVD to generate MVD data when the MVD is not zero; Means for setting a no_update signal indicating whether the MCE is less than the preset threshold; If the MCE is not smaller than the preset threshold, included in the intra coded data and the current picture and the motion compensated block generated by encoding the pixels of the target block based on preset pixels of the current picture. Means for encoding the pixels of the target block based on the current pixels to generate inter coded data provided; Means for generating an intra / inter signal when one of the intra coded data or the inter coded data is selected; Means for determining the frame mode based on the MVD signal, the no_update signal and / or the intra / inter signal Mode signal encoding apparatus comprising a. The method of claim 10, wherein the generating means, Means for calculating the number of bits of said intra coded data and the number of bits of said inter coded data; Means for comparing the number of bits with each other to select a small number of bits; Means for generating an intra / inter signal in response to the small number of bits indicating whether the number of bits of the intra coded data is less than the number of bits of the inter coded data; Means for providing the intra coded data or the inter coded data as the frame coded data in response to the intra / inter signal. Mode signal encoding apparatus comprising a. The method of claim 9, wherein the upper / lower field encoder, When the individual reference fields have M × N pixels and all the pixels of the first and second reference fields are first and second binary values, respectively, the threshold of an error of the upper / lower field for the first reference field is preset. Means for generating a first field indication signal if it is not greater than and generating a second field indication signal if the error of the upper / lower field for the second reference field is not greater than a predetermined threshold; , In the case where the first and second field indication signals are not generated, motion estimation and compensation of the upper / lower field based on one or more previous pictures of the current picture, so that the most of the motion vector and the upper / lower field may be obtained. Means for generating motion vector information comprising a motion compensated field having a similar field; Means for calculating a motion compensation error (MCE) between the upper / lower field and the most similar field and a motion vector difference (MVD) between the motion vector and its predictor; Means for generating a field MVD signal indicating whether the MVD is zero; Means for encoding the MVD to generate MVD data when the MVD is not zero; Means for setting a field no_update signal indicating whether the MCE is less than the preset threshold; If the MCE is not less than the preset threshold, intra-coded data generated by encoding the pixels of the upper / lower field based on preset pixels of the current picture and the current picture and the motion compensated Means for generating the inter coded data provided by encoding the pixels of the upper / lower field based on current pixels included in the field; A field intra / inter signal generator for generating a field intra / inter signal when one of the field intra coded data or the field inter coded data is selected; Means for determining the field mode based on the first / second field indication signal, the field MVD signal, the field no_update signal and / or the field intra / inter signal Mode signal encoding apparatus comprising a. The apparatus of claim 12, wherein the field intra / inter signal generator comprises: Means for calculating the number of bits of the field intra coded data and the number of bits of the field inter coded data; Means for comparing the number of bits with each other to select a small number of bits; Means for generating the field intra / inter signal representing the field intra coded data and the field inter coded data in response to the small number of bits; Means for providing either the field intra coded data or the field inter coded data as the field coded data in response to the field intra / inter signal Mode signal encoding apparatus comprising a. 13. The apparatus of claim 12, wherein the intra coded data is generated by an intra content based arithmetic encoding (CAE) method and the inter coded data is generated by an inter CAE method.