KR100259471B1 - Improved shape coding apparatus and method - Google Patents

Abstract

PURPOSE: An encoding apparatus and a method thereof are to reduce a processing time of an encoding and enhance an encoding effectiveness by partitioning block data into a plurality of sub blocks and performing an encoding using a statistic value of adjacent pixels. CONSTITUTION: A frame memory(102) stores a present frame signal which is extracted from a video signal. An area extension block(104) extends MxM block to Nx N block, where M and N are positive integers and N is greater than M. An area partition block(106) partitions the extended NxN blocks into a plurality of PxP sub blocks, where P is a positive integer. A code table(110) includes n numbers of pattern code words, wherein each of the pattern code words has a plurality of patterns corresponding to the PxP sub blocks and statistic information corresponding to the plurality of the patterns. A pattern determination block(108) stores a previous pixel data of the present frame and determines a pattern code word for encoding the corresponding sub block. A mode adaptive block(112) determines one of the plurality of the patterns as an optimum pattern and calculates statistic values of the corresponding sub block based on the statistic information of the optimum pattern. An encoding block(114) encodes the calculated statistic values by using an arithmetic code.

Description

IMPROVED SHAPE CODING APPARATUS AND METHOD

The present invention relates to an object-based encoding technique for compressing and encoding a video signal at a low bit rate, and more particularly, to an improved shape encoding apparatus and method suitable for encoding a shape of an object in object-based encoding.

As is well known in the art, the transmission of discrete video signals can maintain better image quality than analog signals. When a video signal composed of a series of image "frames" is represented in digital form, a considerable amount of transmission data is generated, especially for high-definition television (HDTV). However, since the usable frequency range of the conventional transmission channel is limited, in order to transmit a large amount of digital data, it is necessary to compress the data to be transmitted and reduce its transmission amount.

Therefore, when transmitting a video signal, the transmitting system compresses and compresses the video signal by using the spatial and temporal correlation of the video signal to reduce the amount of data. To the decryption system.

On the other hand, as the various compression techniques mainly used for encoding an image signal, a hybrid encoding technique combining a stochastic encoding technique and a temporal and spatial compression technique is known to be the most efficient.

Most of the hybrid coding schemes, which are one of the above coding techniques, use motion compensated DPCM (differential pulse code modulation), two-dimensional discrete cosine transform (DCT), quantization of DCT coefficients, VLC (variable modulation coding), and the like. Here, the motion compensation DPCM determines a motion of the object between the current frame and the previous frame, and predicts the current frame according to the motion of the object to generate a differential signal representing the difference between the current frame and the predicted value. Such methods are described, for example, in Staffan Ericsson's "Fixed and Adaptive Predictors for Hybrid Predictive / Transform Coding", IEEE Transactions on Communication, COM-33, NO.12 (December 1985, December), or "A" by Ninomiy and Ohtsuka. motion Compensated Interframe Coding Scheme for Television Pictures ", IEEE Transactions on Communication, COM-30, NO.1 (January, 1982).

More specifically, the motion compensation DPCM predicts the current frame from the previous frame according to the motion of the object estimated between the current frame and the previous frame. Here, the estimated motion may be represented by a two-dimensional motion vector representing the displacement between the previous frame and the current frame. Herein, the pixel displacement of the object is, as is well known, by comparing the block of the current frame with the blocks of the previous frame in units of a predetermined size (for example, 8 ?? 8 size) to determine an optimal matching block. A block-by-block motion estimation technique that estimates the interframe displacement vector (how much the block has moved between frames) for the entire block with respect to the current frame being input, and the pixel value of the current frame in each pixel unit from the pixel values of the previous frame. The motion may be estimated through a pixel-by-pixel motion estimation technique.

Therefore, when transmitting a video signal, the transmitting side compresses and encodes the image signal in the buffer of the output side in order by taking into account the spatial and temporal correlation of the image signal in block units or pixel units through the above-described encoding technique. The image data will be transmitted to the decoding system at the receiving side via the transmission channel at a desired bit rate in response to the channel requirements.

More specifically, the coding system on the transmitting side removes spatial redundancy of the video signal by using transform coding such as discrete cosine transform (DCT), and further uses temporal encoding of motion of the video signal through motion estimation and prediction. By eliminating redundant redundancy, the video signal can be efficiently compressed.

Typically, the DPCM / DCT hybrid coding scheme as described above has a target bitrate of Mbps, and its application fields may be CD-ROM, computer, home appliance (digital VCR, etc.), broadcast (HDTV), etc. It is mainly concerned with MPEG-1, 2 and H.261 coding algorithms related to high bit rate encoding, which mainly consider only the statistical characteristics of the block-by-block motion in the image, which has already been completed by the World Standards Organization.

On the other hand, in recent years, due to the rapid performance improvement and diffusion of PCs, the development of digital transmission technology, the realization of high-definition display devices, the development of memory devices, various devices such as home appliances can process and provide image information with huge data. In order to meet these demands, the transmission and limited capacity of audio-video data through existing low-speed transmission paths (eg, PSTN, LAN, mobile network, etc.) with a bit rate of kbps to meet these demands. New coding techniques with high compression ratios are needed for storage in storage systems.

However, the existing video coding techniques described above are based on local block motion in the entire image regardless of the shape of the moving object and the global motion. Therefore, in the conventional video coding techniques, when the block-by-block motion compensation coding is applied, image quality degradation such as blocking, corner blurring, and spotting appears in the reproduced video that is finally reconstructed. In addition, in order to maintain the resolution for low data transmission, a high compression rate of image data is required. However, the hybrid coding scheme based on the conventional DCT conversion cannot be implemented.

Therefore, at present, there is a need for a standard of a coding scheme for additional compression realization with respect to a coding scheme based on a conventional DCT transformation. In accordance with the needs of the times, MPEG4, which focuses on subjective picture quality based on recent human visual characteristics, is required. The research on low bit rate video encoding technique for the standardization of the standard has been actively conducted everywhere.

In order to meet these needs, potential viable low-rate video coding techniques currently being studied are, for example, wave-based coding and model-based coding to improve existing coding techniques. Object-Based Coding, a kind of coding, Segmentation-Based Coding that divides and encodes an image into a plurality of subblocks, and Fractal Coding that uses image self-similarity Etc. Here, the present invention may be regarded as related to a video object-based encoding technique.

The video object-based coding technique related to the present invention includes an object-oriented analysis-synthesis coding technique, which is described by Michael Hotter, "Object-Oriented Analysis-Synthesis Coding Based on Moving Two." -Dimentional Objects ", Signal Processing: Image Communication 2, pp. 409-428 (December, 1990).

According to the object-oriented analysis and the synthesis coding technique described above, the input video signal is divided into arbitrary objects, and since the motion, the contour, and the pixel data of each object are completely different information due to their data characteristics, the encoding methods are mutually different. They are processed independently, ie, through different coding channels. Therefore, information encoded through separate coding channels may be multiplexed through a multiplexer or the like and sent to a transmitter. Here, the present invention relates to a technique for encoding contour, that is, shape information of an object in an intra mode or an inter mode.

On the other hand, in the existing method of encoding the shape information of the object, obtained in the intra mode for performing the prediction encoding between the shape of the current frame (that is, the outline) and the shape of the previous frame or in the inter mode encoding the shape of the current frame. Probability adaptation was performed using a code table prepared for approximated shape information (ie, contour pixel values), and arithmetic coding of probability values for each symbol (ie, contour pixel values) obtained as a result of such a probability adaptation. ) To transmit to the transmission channel.

That is, in the above-described conventional technique, when encoding a current pixel value to be encoded in one pixel unit in the intra mode, encoding is performed using a probability value thereof by using pixel values in a predetermined range adjacent to the current pixel. As an example, as shown in FIG. 5A, when the current pixel to be encoded is a pixel indicated by a thick solid line and denoted by the reference number A, the adjacent pixels of a1 to a10 in the current frame previously encoded are used. The encoding is performed using the probability values thereof.

In addition, in the above-described conventional technology, in the inter mode, encoding is performed using probability values by using adjacent pixel values of the current frame and adjacent pixel values of the previous frame, that is, as shown in FIGS. 5B and 5C, respectively. As shown, when the current pixel to be encoded is a pixel indicated by a thick solid line and denoted by the reference number A, adjacent pixels of b1-b4 in the current frame previously encoded and adjacent pixels of b5-b8 in the previous frame are encoded. The encoding is performed using the probability values based on these values. 5B illustrates an example of adjacent pixels in the current frame, and FIG. 5C illustrates an example of adjacent four-direction pixels in the previous frame.

That is, in the prior art, as described above, encoding is performed using the probability distribution in one pixel unit in the intra mode or the inter mode.

However, several pixels are grouped (ie, N × N subblocks (e.g., 2 × 2 subblocks) as in the pattern vector quantization technique) without performing encoding by one pixel unit as in the conventional art. If coding is performed using a probability value using adjacent pixels by grouping into 4x4 subblocks, etc., it is possible to greatly shorten processing time for encoding and to improve encoding efficiency.

In addition, performing probability coding in a pattern in which pixels are grouped by several means that a correlation between adjacent pixels is necessarily used, which will lead to an improvement in coding efficiency. That is, in the case of arithmetic coding, the efficiency of coding is improved as the probability value distribution of symbols is pushed to one side. Considering this point, it is very advantageous to concentrate the probability values when grouping and encoding a few pixels.

Accordingly, the present invention devised in view of the above point, divides the N × N block data of the frame area including the contour information into a plurality of sub-blocks, and a plurality of patterns corresponding to the divided sub-blocks An object of the present invention is to provide an improved shape encoding apparatus capable of realizing probability coding using a code table having a plurality of pattern codewords.

Another object of the present invention is to divide N × N block data of a frame area including contour information into a plurality of sub-blocks, refer to neighboring neighboring pixel values, and identify respective patterns corresponding to the divided sub-blocks. There is provided a shape coding method capable of realizing probability coding using a plurality of code tables.

In accordance with one aspect of the present invention, there is provided a form encoding apparatus for encoding a current contour of a current frame including contour information extracted from a video signal to be encoded, using probability coding based on a prepared code table. A frame memory for storing a current frame signal extracted from the video signal; An area extension block extending each M × M block provided in the frame memory into an N × N block having an area at least larger than that, wherein M and N are integers; A region partition block dividing the expanded N × N block provided from the region extension block into a plurality of P × P subblocks, wherein P is an integer; A code table having n pattern codewords each having a plurality of patterns corresponding to the P × P subblocks and probability information corresponding to each of the plurality of patterns; Stores previous pixel data of the current frame that is already encoded before the P × P subblock to be currently encoded, and based on n neighboring pixel values of the current frame adjacent to the corresponding subblock provided from the region partitioning block. A pattern determination block determining one of the n pattern codewords as a pattern codeword for encoding the corresponding subblock; One of the plurality of patterns is determined as an optimal pattern through pattern matching between each of the plurality of patterns in the determined pattern codeword provided in the code table and corresponding subblocks provided from the region partitioning block, and the determined optimal A model adaptation block that calculates probability values for the corresponding subblocks based on probability information on the pattern; And an encoding block which encodes the calculated probability values using an arithmetic code.

According to another aspect of the present invention, there is provided a present invention including differential contour information obtained through subtraction between a current frame including an extracted current contour signal and a previous frame including an extracted previous contour signal. A shape encoding apparatus for encoding the difference contour information of a frame through probability coding based on a prepared code table, comprising: a first frame memory for storing a current frame signal including the difference contour information; An area extension block extending each M × M block provided in the frame memory into an N × N block having an area at least larger than that, wherein M and N are integers; A region partition block dividing the expanded N × N block provided from the region partition block into a plurality of P × P subblocks, wherein P is an integer; A code table having n pattern codewords each having a plurality of patterns corresponding to the P × P subblocks and probability information corresponding to each of the plurality of patterns; A second frame memory for storing each pixel data of a previous frame including previously encoded previous difference contour information, and storing previous pixel data of the current frame that is already encoded before a P × P subblock to be currently encoded; The n patterns on the basis of n peripheral pixel values of the base-coded current frame adjacent to the sub-block provided from the region dividing block and n peripheral pixel values of the previous frame adjacent to the sub-block. A pattern determination block that determines one of codewords as a pattern codeword for encoding the corresponding subblock; One of the plurality of patterns is determined as an optimal pattern through pattern matching between each of the plurality of patterns in the determined pattern codeword provided in the code table and corresponding subblocks provided from the region partitioning block, and the determined optimal A model adaptation block that calculates probability values for the corresponding subblocks based on probability information on the pattern; And an encoding block which encodes the calculated probability values using an arithmetic code.

According to another aspect of the present invention, there is provided a form encoding method for encoding a current outline of a current frame including contour information extracted from a video signal to be encoded, using probability coding based on a prepared code table. The code table comprises n pattern codewords each having a plurality of patterns and probability information corresponding to each of the plurality of patterns, and the encoding method comprises: a predetermined number of current frame signals extracted from the video signal; Dividing into M × M blocks, wherein N is an integer; Expanding each of the divided M × M blocks into N × N blocks each having at least a larger area, wherein M is an integer; Dividing each of the expanded N × N blocks into a plurality of P × P subblocks, wherein P is an integer; A fourth step of determining neighboring n pixel values adjacent to each of the divided sub-blocks among the pixel data of the current frame that is already encoded; A fifth step of determining any one of the n pattern codewords as a pattern codeword for encoding the corresponding subblock based on the determined n neighboring pixel values adjacent to each of the divided subblocks; One of the plurality of patterns is determined as an optimal pattern through pattern matching between each of the plurality of patterns in the determined pattern codeword and the corresponding subblocks, and based on probability information for the determined optimal pattern, the corresponding subblocks are assigned to the corresponding subblocks. A sixth step of calculating probability values And a seventh step of encoding the calculated probability values using an arithmetic code.

According to another aspect of another aspect of the present invention, a present invention includes differential contour information obtained by subtraction between a current frame including an extracted current contour signal and a previous frame including an extracted previous contour signal. In the form encoding method for encoding the difference contour information of a frame through probability coding based on a prepared code table, the code table includes n pattern codes each having a plurality of patterns and probability information corresponding to each of the plurality of patterns. The encoding method comprises: a first step of dividing a current frame signal extracted from the video signal into a plurality of predetermined M × M blocks, wherein N is an integer; Expanding each of the divided M × M blocks into N × N blocks each having at least a larger area, wherein M is an integer; Dividing each of the expanded N × N blocks into a plurality of P × P subblocks, wherein P is an integer; A fourth step of determining neighboring n pixel values adjacent to each of the divided sub-blocks among the pixel data of the current frame that is already encoded; A fifth step of determining neighboring n pixel values adjacent to each of the divided sub-blocks among the pixel data of the base-coded previous frame; Based on the determined n neighboring pixel values of the current frame and the determined n neighboring pixel values of the previous frame, any one of the n pattern codewords is determined as a pattern codeword for encoding the corresponding subblock. Sixth step; One of the plurality of patterns is determined as an optimal pattern through pattern matching between each of the plurality of patterns in the determined pattern codeword and the corresponding subblocks, and based on probability information for the determined optimal pattern, the corresponding subblocks are assigned to the corresponding subblocks. A seventh step of calculating probability values And an eighth step of encoding the calculated probability values using an arithmetic code.

1 is a block diagram of an improved shape coding apparatus according to a preferred embodiment of the present invention;

2 illustrates an example of block data in which an M × M block is expanded to an N × N block according to the present invention, 2a illustrates an example of an M × M block, and 2b illustrates an example of an extended N × N block. One drawing,

FIG. 3 illustrates an example of referring to neighboring pixel values adjacent to a corresponding subblock when determining a code table of a P × P subblock to be partitioned according to the present invention. FIG. 3A illustrates a case of intra mode encoding. And 3c shows a case of inter mode encoding, respectively;

4 is a view showing a pattern example of each sub block when dividing an M × M block into a plurality of 2 × 2 subblocks according to the present invention;

FIG. 5 illustrates an example of referring to neighboring neighboring pixel values when performing probability coding in units of one pixel according to a conventional method, in which 5a represents intra mode encoding and 5b and 5c represent inter mode encoding. Figures showing cases respectively.

<Description of the code | symbol about the principal part of drawing>

102109: Frame memory 104: Area Expansion Block

106: region division block 108: pattern determination block

110: code table 112: model determination block

114: coding block

The above and other objects and various advantages of the present invention will become more apparent from the preferred embodiments of the present invention described below with reference to the accompanying drawings by those skilled in the art.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, the most characteristic technical gist of the present invention is not to perform the pixel by one pixel when performing contour coding on the contour as in the above-mentioned prior art, but to group several pixels, that is, N × N as in the pattern vector quantization technique. Grouping into subblocks (e.g., 2x2 subblocks, 4x4 subblocks, etc.) performs encoding with a probability value using a pattern codeword based on adjacent pixels. That is, it is possible to shorten the processing time for encoding and to increase the efficiency of encoding.

Further, in the present invention, probability coding is performed in a pattern in which pixels are grouped several times, which means that a correlation between adjacent pixels is necessarily used, and the efficiency of encoding can be further improved. That is, in the case of arithmetic coding, the efficiency of coding is improved as the probability value distribution of symbols is pushed to one side. In view of such a point, as in the present invention, when grouping and encoding a few pixels as in the present invention, it is very advantageous to concentrate the probability values. to be.

1 shows a block diagram of an improved shape coding apparatus according to a preferred embodiment of the present invention.

As shown in the figure, the shape coding apparatus of the present invention includes a first frame memory 102, an area extension block 104, an area division block 106, a pattern determination block 108, and a second frame memory 109. ), Code table 110, model adaptation block 112, and undersignal block 114.

Referring to FIG. 1, in the first frame memory 102, shape information (that is, outline information) extracted through shape detection means (not shown) is stored in units of frames. In the mode, it will be the entire contour information of one frame, and in the inter mode, it will be the error signal obtained through the motion compensation between the current frame and the previous frame, that is, the differential contour information.

Next, in the area expansion block 104, the MxM block data including the contours provided from the frame memory 102 is expanded into NxN block data having at least a large area, that is, shown in FIG. 2A as an example. As shown in FIG. 2B, the 16 × 16 block data as shown in FIG. 2B is expanded to 18 × 18 block data, and the expanded N × N block data is the next region. Provided as split block 106. In FIG. 2B, reference numeral A denotes an original M × M block region, and reference numeral B denotes an extended region.

In this case, each pixel value of the extended area B may be calculated using adjacent pixel values of the M × M block area. That is, as an example, as shown in Fig. 2B, five pixel values of the extended area B filled with diagonal lines and indicated by the reference numeral b are adjacent four pixel values filled with diagonal lines and indicated by the reference numeral a in the M × M block area. Can be replaced by their average.

Here, the reason for extending the M × M block data is that the P × P subblock (eg, 2 × 2 sub) is selected when the optimal code table is selected for probability coding using a plurality of code tables having respective patterns. Blocks, 4x4 sub-blocks, etc.) are used to generate adjacent pixel values for pixel values located on each side of the NxN block.

In the area dividing block 106, the MxM blocks (e.g., 16x16 blocks) are each divided into a plurality of PxP subblocks (e.g., 2x2 subblocks or 4x4 subblocks). Partitioning, for example, as shown in FIG. 2A, divides a 16 × 16 block into 64 2 × 2 subblocks, where the divided P × P subblocks are pattern determined block 108 and model via line L11. Each is provided to an adaptation block 112. At this time, when the M × M block is divided into 64 2 × 2 subblocks, each subblock will have any one of 16 patterns as shown in FIG. 4.

Meanwhile, the pattern determination block 108 selects a corresponding code table from among the plurality of code tables prepared in the code table 110 based on neighboring pixel values adjacent to each of the sub blocks provided through the line L11. Decide

That is, assuming that an M × M block is divided into 64 2 × 2 subblocks, a total of 64 pattern codewords having 16 patterns and probability values corresponding to each pattern are prepared in the code table 110. In the pattern determination block 108, a sub-item of a plurality of pattern codewords prepared based on an encoding mode signal provided from a system controller (eg, a microprocessor), not shown, and peripheral pixel values adjacent to the sub-block. One pattern codeword most suitable for the block is determined.

For example, when the current encoding mode is an intra mode, in the pattern determination block 108, as shown in FIG. 3A as an example, six neighboring pixels that have already been encoded in the current frame adjacent to the corresponding subblock A are shown. Based on the values a1-a6, one pattern codeword most suitable for the corresponding subblock among the plurality of pattern codewords in the code table is determined. That is, as an example, the pattern codeword may have a value from "000000" to "111111", and each of these pattern codewords has 16 patterns as shown in FIG. 4 and probability values corresponding to each pattern, respectively. .

In this case, the pixel data already encoded in the current frame is provided from the second frame memory 109. The second frame memory 109 stores the already encoded pixel data in the current frame and pixel data of the extended region. Also, the pixel data of the previous frame and the pixel data of the extended area are stored. Here, the already encoded pixel data in the current frame and the pixel data of the extended region are used to determine the pattern codeword of each sub-block during intra mode encoding, and the pixel data of the previous frame and the pixel data of the extended region are interleaved. It is used to determine the pattern codeword of each subblock in mode encoding.

Further, when the current encoding mode is the inter mode, in the pattern determination block 108, as shown in FIG. 3B as an example, three peripheral pixel values of the already encoded current frame adjacent to the corresponding subblock A are shown. Three peripheral pixel values b4 and b5 adjacent to the previous subblock A 'in the previous frame at the position corresponding to the corresponding subblock A as shown in (b1, b2, b3) and FIG. 3C. , b6) determines one pattern codeword that is most suitable for the corresponding subblock among the plurality of pattern codewords in the code table.

In this case, when the 16x16 block is divided into a plurality of 4x4 subblocks and subjected to probability coding, neighboring neighboring pixels of the currently encoded current frame, which are referred to for determining the pattern codeword, are 11 pixels, for example. It may be composed of

Therefore, in the code table 110, the pattern adaptation block which will be described later through the line L13 the pattern codeword information determined in the intra mode or the inter mode through the process described above, that is, the pattern information included in the determined pattern codeword. Will be provided at 112. Of course, the same decoding table as the transmitting encoder is prepared in the decoding device on the receiving side.

On the other hand, in the model adaptation block 112, a plurality of respective patterns in the determined pattern codeword provided in the code table 110 via the line L13 and the divided P × P provided from the region dividing block 106 via the line L11. Pattern matching between subblocks (e.g., 2x2 subblocks) is detected to detect an optimal pattern corresponding thereto, and probability values for each subblock divided by using probability information corresponding to the detected pattern are detected. It is adaptively calculated, and the probability values for each subblock calculated here are provided to the coding block 114 described later through the line L15.

Accordingly, the coding block 114 encodes the probability values provided by the model adaptation block 112 through the line L15 using, for example, binary arithmetic code of a Joint Photographic Experts Group (JPEG). The probability values encoded in this manner are transmitted to a transport channel for transmission to a remote receiver.

As described above, according to the present invention, when probabilistic encoding the contour detected from the video signal in the intra mode or the inter mode for object-based encoding, several pixels are not performed one by one as in the conventional method. By dividing into grouped N × N subblocks (eg, 2 × 2 subblocks, 4 × 4 subblocks, etc.) and performing encoding with probability values using neighboring pixels, the encoding process is shortened as well as encoding. The efficiency can be greatly improved.

Claims (19)

A shape encoding apparatus for encoding a current contour of a current frame including contour information extracted from a video signal to be encoded by probability coding based on a prepared code table, A frame memory for storing a current frame signal extracted from the video signal; An area extension block extending each M × M block provided in the frame memory into an N × N block having an area at least larger than that, wherein M and N are integers; A region partition block dividing the expanded N × N block provided from the region extension block into a plurality of P × P subblocks, wherein P is an integer; A code table having n pattern codewords each having a plurality of patterns corresponding to the P × P subblocks and probability information corresponding to each of the plurality of patterns; Stores previous pixel data of the current frame that is already encoded before the P × P subblock to be currently encoded, and based on n neighboring pixel values of the current frame adjacent to the corresponding subblock provided from the region partitioning block. A pattern determination block determining one of the n pattern codewords as a pattern codeword for encoding the corresponding subblock; One of the plurality of patterns is determined as an optimal pattern through pattern matching between each of the plurality of patterns in the determined pattern codeword provided in the code table and corresponding subblocks provided from the region partitioning block, and the determined optimal A model adaptation block that calculates probability values for the corresponding subblocks based on probability information on the pattern; And An improved shape encoding apparatus comprising an encoding block for encoding the calculated probability values using an arithmetic code. 2. The apparatus of claim 1, wherein the M × M block has a size of 16 × 16 blocks. 3. The apparatus of claim 2, wherein the extended N × N block has a size of 18 × 18 blocks. 3. The apparatus of claim 2, wherein each of the divided PxP subblocks has a size of 2x2 subblocks. 3. The apparatus of claim 2, wherein each of the divided PxP subblocks has a size of 4x4 subblocks. The apparatus according to claim 4 or 5, wherein the number of patterns in each pattern codeword is determined by the number of pixels of the divided subblocks. 2. The apparatus of claim 1, wherein the number of n pattern codewords in the code table is determined by the number of n peripheral pixels of the current frame adjacent to the divided subblock. 8. The apparatus of claim 7, wherein the number of adjacent neighboring pixels is six and the pattern codeword is 64. In the form encoding method for encoding the current contour of the current frame including the contour information extracted from the video signal to be encoded through a probability coding based on the prepared code table, The code table includes n pattern codewords each having a plurality of patterns and probability information corresponding to each of the plurality of patterns, The encoding method is: A first step of dividing a current frame signal extracted from the video signal into a plurality of predetermined M × M blocks, wherein N is an integer; Expanding each of the divided M × M blocks into N × N blocks each having at least a larger area, wherein M is an integer; Dividing each of the expanded N × N blocks into a plurality of P × P subblocks, wherein P is an integer; A fourth step of determining neighboring n pixel values adjacent to each of the divided sub-blocks among the pixel data of the current frame that is already encoded; A fifth step of determining any one of the n pattern codewords as a pattern codeword for encoding the corresponding subblock based on the determined n neighboring pixel values adjacent to each of the divided subblocks; One of the plurality of patterns is determined as an optimal pattern through pattern matching between each of the plurality of patterns in the determined pattern codeword and the corresponding subblocks, and based on probability information for the determined optimal pattern, the corresponding subblocks are assigned to the corresponding subblocks. A sixth step of calculating probability values And And a seventh step of encoding the calculated probability values using an arithmetic code. Through the probability coding based on the prepared code table, the differential contour information of the current frame including the differential contour information obtained by subtraction between the current frame including the extracted current contour signal and the previous frame including the extracted previous contour signal is obtained. In the form encoding device to encode, A first frame memory for storing a current frame signal including the difference contour information; An area extension block extending each M × M block provided in the frame memory into an N × N block having an area at least larger than that, wherein M and N are integers; A region partition block dividing the expanded N × N block provided from the region partition block into a plurality of P × P subblocks, wherein P is an integer; A code table having n pattern codewords each having a plurality of patterns corresponding to the P × P subblocks and probability information corresponding to each of the plurality of patterns; A second frame memory for storing each pixel data of a previous frame including previously encoded previous difference contour information, and storing previous pixel data of the current frame that is already encoded before a P × P subblock to be currently encoded; The n patterns on the basis of n peripheral pixel values of the base-coded current frame adjacent to the sub-block provided from the region dividing block and n peripheral pixel values of the previous frame adjacent to the sub-block. A pattern determination block that determines one of codewords as a pattern codeword for encoding the corresponding subblock; One of the plurality of patterns is determined as an optimal pattern through pattern matching between each of the plurality of patterns in the determined pattern codeword provided in the code table and corresponding subblocks provided from the region partitioning block, and the determined optimal A model adaptation block that calculates probability values for the corresponding subblocks based on probability information on the pattern; And An improved shape encoding apparatus comprising an encoding block for encoding the calculated probability values using an arithmetic code. 12. The apparatus of claim 10, wherein the M × M block has a size of 16 × 16 blocks. 12. The apparatus of claim 11, wherein the extended N × N block has a size of 18 × 18 blocks. 12. The apparatus of claim 11, wherein each of the divided PxP subblocks has a size of 2x2 subblocks. 12. The apparatus according to claim 11, wherein each of the divided PxP subblocks has a size of 4x4 subblocks. 15. The apparatus of claim 13 or 14, wherein the number of patterns in each pattern codeword is determined by the number of pixels of the divided subblocks. 11. The method of claim 10, wherein the number of n pattern codewords in the code table is determined by the sum of the number of n peripheral pixels of the current frame and the number of n peripheral pixels of the previous frame adjacent to the divided subblock. Improved shape coding apparatus, characterized in that determined. 17. The improved form of claim 16, wherein the n neighboring pixels of the previous frame adjacent to the divided sub-block are at least neighboring pixels at positions not overlapping with the n neighboring pixels of the current frame. Encoding device. 18. The method of claim 16 or 17, wherein the number of adjacent neighboring pixels of the current frame is three, the number of adjacent neighboring pixels of the previous frame is three, and the pattern codeword is 64. Improved shape coding device. Through the probability coding based on the prepared code table, the differential contour information of the current frame including the differential contour information obtained by subtraction between the current frame including the extracted current contour signal and the previous frame including the extracted previous contour signal is obtained. In the form encoding method to encode, The code table includes n pattern codewords each having a plurality of patterns and probability information corresponding to each of the plurality of patterns, The encoding method is: A first step of dividing a current frame signal extracted from the video signal into a plurality of predetermined M × M blocks, wherein N is an integer; Expanding each of the divided M × M blocks into N × N blocks each having at least a larger area, wherein M is an integer; Dividing each of the expanded N × N blocks into a plurality of P × P subblocks, wherein P is an integer; A fourth step of determining neighboring n pixel values adjacent to each of the divided sub-blocks among the pixel data of the current frame that is already encoded; A fifth step of determining neighboring n pixel values adjacent to each of the divided sub-blocks among the pixel data of the base-coded previous frame; Based on the determined n neighboring pixel values of the current frame and the determined n neighboring pixel values of the previous frame, any one of the n pattern codewords is determined as a pattern codeword for encoding the corresponding subblock. Sixth step; One of the plurality of patterns is determined as an optimal pattern through pattern matching between each of the plurality of patterns in the determined pattern codeword and the corresponding subblocks, and based on probability information for the determined optimal pattern, the corresponding subblocks are assigned to the corresponding subblocks. A seventh step of calculating probability values And And an eighth step of encoding the calculated probability values using an arithmetic code.

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