KR20060079051A - Color image encoding and decoding method and apparatus using a correlation between chrominance components - Google Patents

Abstract

The present invention relates to a method and apparatus for encoding and decoding a color image with a smaller data amount by using the correlation between the color difference components of the color image. The encoding method according to the present invention provides a plurality of color difference components of the color image. Converts each of the inter-prediction modes, calculates the cost of each inter-prediction mode using a predetermined cost function, and calculates a plurality of After selecting one of the inter-prediction modes, the transform value of the selected mode is output, and the entropy encoding is performed on the output transform value, thereby increasing the compression ratio of the compressed image without degrading the image quality.

Description

Color image encoding and decoding method and apparatus using a correlation between chrominance components}

FIG. 1 is a diagram illustrating data constituting an image of an RGB format and an image of a YCbCr format.

2 is a diagram showing the configuration of video data in 4: 4: 4, 4: 2: 2, and 4: 2: 0 formats.

3 is a block diagram of a video encoding apparatus according to an embodiment of the present invention.

4 is a reference diagram for explaining calculation of a color difference component transform value according to an embodiment of the present invention.

FIG. 5 is a detailed block diagram of the color difference component converter 330 of FIG. 3.

6 is a flowchart of an encoding method according to an embodiment of the present invention.

7 is a block diagram of a decoding apparatus according to an embodiment of the present invention.

8 is a flowchart of a decoding method according to an embodiment of the present invention.

9 is a table illustrating an interprediction mode applied to an embodiment of the present invention.

FIG. 10 is a table for explaining a reverse interpretation method for each inter prediction mode.

FIG. 11 is a detailed block diagram illustrating another example of the color difference component converter 330 of FIG. 3.

12 is a block diagram illustrating a selected interprediction mode for each macroblock in one picture.

13 (a) (b) (c) (d) (e) are diagrams showing the interprediction mode plane according to the present invention.

14 (a) to (d) are diagrams for explaining a method of encoding interprediction mode information according to the present invention.

15 is a flowchart illustrating a method of encoding interprediction mode information according to an embodiment of the present invention.

16 is a flowchart illustrating a decoding method according to an embodiment of the present invention.

The present invention relates to encoding and decoding of color image data, and more specifically, to find a correlation between color difference components (Cb, Cr) of color image data configured in YCbCr format, to encode color image data with a smaller data amount, The present invention relates to a method and an apparatus for decoding the same.

FIG. 1 is a diagram illustrating data constituting an image of an RGB format and an image of a YCbCr format.

One of the formats for expressing a color image is the RGB format, which expresses the color components of the image by dividing the color components into three color components (Red, Green, Blue, hereinafter R, G, and B). At this time, all three color components (R, G, B) are composed of the same data amount. For example, if there are 16x16 macroblocks, the R, G, and B components are each 16x16 in size. However, the human eye is more sensitive to the luminance component that represents brightness than the chrominance component that represents color. Therefore, the data amount can be reduced by using a format in which a color image is divided into a luminance component and a chrominance component, and this format is called a YCbCr format.

The YCbCr format allocates more data to the luminance component than to the chrominance component. Referring to FIG. 1, when an RGB format image of a 16x16 macroblock is represented as an YCbCr format image, it can be seen that a 16x16 luminance block and an 8x8 chrominance block Cb and Cr are formed. At this time, Y, Cb, Cr values which are luminance components and chrominance components are calculated by weighted combination of R, G, and B values. For example, Y, Cb, Cr values are calculated by the formula Y = 0.29900R + 0.58700G + 0.11400B, Cb = -0.16874R-0.33126G + 0.50000B, Cr = 0.50000R-0.41869G-0.08131B do. As described above, the color video data of the YCbCr format includes a luminance component and two color difference components, and each component is separately encoded during encoding. That is, the coding is performed without considering any correlation between the color difference components.

2 is a diagram showing the configuration of video data in 4: 4: 4, 4: 2: 2, and 4: 2: 0 formats.

When encoding a moving picture, the color format of the moving picture is represented by displaying a ratio of luminance components and chrominance components of pixels included in horizontal pixel lines of a picture constituting the moving picture. Hereinafter, the luminance component is represented by Y, and the color difference component is represented by Cb and Cr. Luminance refers to the degree of image brightness. In ITU-R recommendation, the luminance of one pixel is represented by 8 bits. The color difference is information representing the color of an image and represents the color of a pixel by two 8-bit values Cb and Cr. The coordinate system that represents color is called a color space. In MPEG, which is a video encoding standard, a color format of a video is represented by three 8-bit information such as Y, Cb, and Cr.

In expressing color video using Y, Cb and Cr, there can be various color formats according to the ratio. Even in different color formats, the Y component, which is the luminance component, is the same and only the Cb and Cr components are different. . Referring to FIG. 2, an image of a 4: 2: 2 format is obtained by ½ down sampling a color difference component of a 4: 4: 4 format image in a horizontal direction. It can be seen that an image of 4: 2: 0 format is obtained.

As described above, in the conventional general codecs (MPEG, H.26x, and VC1), RGB color images are converted into YCbCr color images, and luminance and chrominance components are separately encoded. At this time, it may have various formats such as 4: 4: 4, 4: 2: 2, 4: 2: 0, etc. In general, YCbCr is 4: 2: 0 format video data in MPEG, H.26x, and VC1. Receives and encodes. Hereinafter, image data of 4: 2: 0 format will be described as an example.

In a general video encoding method, input Y, Cb, and Cr components are encoded such that there is no temporal and spatial redundancy with each other. Spatial redundancy is eliminated through intra prediction, which is prediction with neighboring blocks, and temporal redundancy is eliminated by interpretation between previous and current pictures. That is, only intra-prediction encodes the difference component between the neighboring block and the current block, and inter-prediction encodes only the difference component between the previous picture and the current picture to increase the compression efficiency.

That is, in the related art, prediction is performed to remove temporal and spatial redundancy in the Y, Cb, and Cr components. Thus, redundancy removal using the correlation between the Y, Cb, and Cr components is not performed. However, in order to compress high-definition images such as H.264 high profile, the amount of data of Y, Cb, and Cr components increases, so a method of efficiently compressing them is required.

Accordingly, an object of the present invention is to provide a color image encoding apparatus and method for increasing encoding speed by reducing and encoding a size of data to be encoded using correlation between Cb and Cr components constituting a color difference component of a color image, An apparatus and method for decoding the same are provided.

According to an embodiment of the present invention, the color difference component Cb and Cr values of a color image are weighted and combined with predetermined coefficients to form a plurality of transformed values, and a predetermined cost function is obtained from the generated transformed values. A color difference component converter for selecting and outputting two transform values having the smallest calculated cost; And an entropy coding unit for performing entropy encoding on the selected transform value.

If the chrominance components Cb and Cr have already been converted and quantized, or if the chrominance components Cb and Cr are values before the transform and quantization are performed, the chrominance components Cb and Cr are transformed and quantized with respect to the converted values output from the chrominance component converter. It is preferable to further include a transform and quantization unit for performing the.

The color difference component converting unit calculates a conversion value of the color difference component by ax Cb + bx Cr + c, wherein the a, b, c values are constants, and a plurality of (a, b, c) pairs are predetermined by the user. Preferably, the predetermined cost function preferably includes RDcost, SAD, SATD, SSA and MAD.

The chrominance component converter may further include: a conversion value calculator configured to calculate a conversion value in all cases that can be made by weighting and combining a plurality of (a, b, c) coefficients when the chrominance components Cb and Cr are input; A cost calculator configured to calculate a cost with respect to the converted value by a predetermined cost function; And a determination unit which selects and outputs a conversion value in two cases having the smallest value among the calculated cost values.

In addition, the chrominance component converting unit preferably encodes information on coefficients (a, b, c) corresponding to two transform values having the smallest cost according to a run length encoding method.

In addition, the technical problem is a conversion value calculation unit for calculating a conversion value in all cases that can be made by weighting and combining a plurality of (a, b, c) coefficients when the color difference component Cb, Cr is input; A cost calculator configured to calculate a cost with respect to the converted value by a predetermined cost function; A determination unit which selects and outputs a conversion value in two cases having the smallest value among the calculated cost values; And an entropy coding unit for entropy encoding the output transform value.

In addition, the technical problem is to (a) weight and combine the Cb, Cr values, which are color difference components of a color image, with predetermined coefficients to form a plurality of transformed values, and calculates a predetermined cost function among the transformed values. Selecting and outputting two converted values having the smallest cost; And (b) an entropy coding step of performing entropy coding on the selected transform value.

The step (a) may include: (a1) calculating conversion values in all cases that may be made by weighting and combining a plurality of (a, b, c) coefficients when the color difference components Cb and Cr are input; (a2) a cost calculation step of calculating a cost with respect to the converted conversion value by a predetermined cost function; And (a3) selecting and outputting the converted values in two cases having the smallest value among the calculated cost values.

In the step (b), it is preferable that the information about the coefficients (a, b, c) corresponding to the two smallest transformed values determined by the step (a) is encoded according to the run length encoding method.

On the other hand, according to another field of the present invention, the technical problem is an entropy decoding unit for entropy decoding the encoded bit stream; And bypassing when the decoded data is a luminance component, and extracting information about coefficients used to weight and combine the Cb and Cr components when the decoded data is a luminance component, thereby extracting the original color difference components Cb and Cr components. It is also achieved by a decoding apparatus comprising a color difference component inverse transform unit which is generated and output.

 The color-difference component inverse transform unit is information on which (a, b, c) coefficient pairs are encoded, and calculates the Cb and Cr components by extracting the transmitted and encoded information according to a run length encoding method. desirable.

In addition, the technical problem is (a) entropy decoding step of entropy decoding the encoded bit stream; And (b) if the decoded data is a luminance component, bypasses it, and in the case of a chrominance component, extracts information about coefficients used to weight and combine the Cb and Cr components to obtain the chrominance components Cb and Cr components. It is also achieved by a decoding method comprising the step of making and outputting the.

In addition, the technical problem is that in the encoding apparatus for a color image according to the present invention, the color difference component of the color image is converted into two or more interprediction modes, and the values converted by the modes are interpolated using a predetermined cost function. A chrominance component converter for calculating a raw cost for each prediction mode, selecting one of the two or more interprediction modes according to the calculation result, and outputting a conversion value of the selected mode; And an entropy encoding unit for performing entropy encoding on the output transform value.

The selection of the interprediction mode is performed in units of a predetermined block, and the interpretation mode information selected for the predetermined block is encoded in a group unit of a plurality of blocks.

It is preferable to generate a plurality of mode planes that classify interprediction mode information for a plurality of blocks in a predetermined group for each mode, and to encode the generated plurality of mode planes.

The generated mode plane preferably includes information indicating whether an interprediction mode corresponding to a current mode plane is applied for each of the predetermined blocks.

In the predetermined mode plane, the mode information corresponding to the block to which the interprediction mode corresponding to the current mode plane is applied is '1', and the mode information corresponding to the block to which the interprediction mode corresponding to the current mode plane is not applied. Is preferably obtained by setting to '0'.

Generates a plurality of mode planes that classify interprediction mode information for a plurality of blocks in a predetermined group for each mode, arranges the generated plurality of mode planes in a predetermined order, and mode information of a previous mode plane. Therefore, it is preferable to transform the information of the next mode plane and to encode the modified mode plane.

The generated mode plane includes information indicating whether or not an interprediction mode corresponding to a current mode plane is applied for each of the predetermined blocks, and the modification of the information of the mode plane is based on the information of the previous mode plane. On the basis of this, it is preferable to delete the information on the block to which the interprediction mode of the previous mode plane is applied among the information of the next mode plane.

In the predetermined mode plane, the mode information corresponding to the block to which the interprediction mode corresponding to the current mode plane is applied is '1', and the mode information corresponding to the block to which the interprediction mode corresponding to the current mode plane is not applied. Is preferably obtained by setting to '0'.

The deletion of the information on the block to which the interprediction mode according to the previous mode is applied is preferably performed by setting the information on the block to which the interprediction mode according to the previous mode is applied to '0'.

Preferably, the predetermined block is a macroblock, and the group is a picture.

The chrominance component converter may include an interprediction mode table storage unit configured to store an interprediction mode table including two or more interprediction modes; A conversion value calculator configured to calculate Cb and Cr values, which are color difference components of a color image, for each mode based on the interprediction mode table; It is preferable to include a mode selection part which selects the interprediction mode with the smallest cost computed by the predetermined cost function among the calculated conversion values.

The apparatus may further include a run length encoding unit configured to perform run length encoding on the selected interprediction mode information.

According to another aspect of the present invention, there is provided a method of encoding a color image according to an embodiment of the present invention, wherein the color difference component of the color image is converted into two or more interprediction modes, and the values converted by the modes are converted using a predetermined cost function. Calculating a cost for each mode, selecting one of the two or more interprediction modes according to the calculation result, and outputting a conversion value of the selected mode; It is achieved by the encoding method comprising the step of performing entropy encoding on the output transform value.

In addition, the technical problem is an apparatus for decoding an encoded color image, an entropy decoding unit for entropy decoding the input bit stream; And a chrominance component inverse transform unit for restoring an original chrominance component based on interprediction mode information applied to a current block having a predetermined size extracted from the bit stream, wherein the interprediction mode information includes two or more interpreions. Among the dictation modes, an interprediction mode applied to the current block is indicated, and the original color difference component is obtained from a transform value corresponding to the interprediction mode applied to the current block.

In addition, the present invention provides a method of decoding an encoded color image, comprising: entropy decoding an input bit stream; Restoring an original chrominance component based on interprediction mode information applied to a current block of a predetermined size extracted from the bit stream, wherein the interprediction mode information includes two or more interprediction modes. Among them, an interprediction mode applied to the current block, wherein the original color difference component is obtained from a transform value corresponding to the interprediction mode applied to the current block.

In addition, the technical problem is to convert the color difference component of the color image for each of the two or more interprediction mode, and to calculate the cost for each mode by using a predetermined cost function, the value converted for each mode, according to the calculation result Selecting one of two or more interprediction modes and outputting a conversion value of the selected mode; It is also achieved by a computer readable recording medium having recorded thereon a program for executing a method of encoding a color image comprising performing entropy encoding on the output converted value.

In addition, the technical problem is the step of entropy decoding the input bit stream; Restoring an original chrominance component based on interprediction mode information applied to a current block of a predetermined size extracted from the bit stream, wherein the interprediction mode information includes two or more interprediction modes. Among them, an interprediction mode applied to the current block, and the original color difference component is obtained from a transform value corresponding to the interprediction mode applied to the current block. It is also achieved by a computer readable recording medium having recorded thereon a program.

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

3 is a block diagram of a video encoding apparatus according to an embodiment of the present invention.

The encoding apparatus includes a motion estimator 302, a motion compensator 304, an intra prediction performer 306, a transform unit 308, a quantization unit 310, a reordering unit 312, and an entropy coding unit 314. , An inverse quantization unit 316, an inverse transform unit 318, a filter 320, and a frame memory 322.

The encoding apparatus encodes the macroblock of the current picture in one encoding mode selected from various encoding modes. To this end, encoding is performed under all modes that inter-prediction and intra-prediction can have, and the rate-distortion cost (RDcost) is calculated to determine the mode with the smallest value as the optimal mode and encoding under that mode. Perform Rate (Rate, R) means a bit rate and represents the number of bits used to encode one macroblock. That is, the rate is the sum of the number of bits obtained by encoding the residual signal after the interprediction or intra prediction is performed and the number of bits obtained by encoding the motion vector information. Distortion (D) is the difference between the original macroblock and the decoded macroblock when the encoded image is decoded. Therefore, the distortion D is a value that can be known when decoding is performed and the original macro block is restored.

However, the determination of the optimal mode in the encoding mode determination method of the present invention may be performed by various methods as well as the calculation of the rate-distortion cost. That is, not only the RDCost but also the cost calculation may be performed by various methods. For example, the cost functions that can be used are sum of absolute value (SAD), sum of absolute transformed difference (SATD), sum of squared difference (SSD), mean of absolute difference (MAD), and Laglange function Etc.

Finding the predicted value of the macro block of the current picture in the reference picture for interprediction is performed by the motion estimation unit 302. When the reference block is found in units of 1/2 or 1/4 pixels, the motion compensator 304 determines the reference block data value by calculating these intermediate pixel values. In this way, the interprediction is performed by the motion estimator 302 and the motion compensator 304.

In addition, the intra prediction unit 306 that finds the prediction value of the macro block of the current picture in the current picture is performed by the intra prediction unit 306. Whether to perform inter-prediction or intra-prediction on the current macro block is calculated by calculating the rate-distortion cost under all encoding modes and determining the mode in which the value is the smallest as the encoding mode of the block. Perform encoding on.

As described above, if inter prediction or intra prediction is performed and prediction data to be referred to by the macro block of the current frame is found, it is input to the color difference component converter 330 by subtracting it from the macro block of the current picture. When the color difference component is input, the color difference component converting unit 330 makes the color difference component into various conversion values according to the color difference component conversion method described later, and selects two conversion values from the color difference component. If a luminance component other than a chrominance component is input, it is passed as it is. The luminance component or the selected color difference component is input to the transform unit 308 to perform the transformation, and then the quantization unit 310 performs quantization. The subtraction of the motion estimation reference block from the macroblock of the current frame is called a residual. The data input to the chrominance component converter 330 to reduce the amount of data during encoding is a residual value. The quantized residual value passes through the reordering unit 312 for encoding by the entropy coding unit 314.

Meanwhile, in order to obtain a reference picture to be used for interprediction, the current picture is reconstructed through the inverse quantizer 316 and the inverse transform unit 318. The reconstructed current picture is stored in frame memory and used to perform interprediction on the next picture. When the reconstructed picture passes the filter 320, the picture is a picture including some encoding error in the original picture.

In addition, the detailed operation of the color difference component conversion unit 330 is as follows. When the Cb and Cr data, which are luminance components, are input, a conversion value is calculated according to the following equation (1).

Transformation = a x Cb + b x Cr + c

Here, a, b and c values can be determined by experiment. For example, in the case of interpretation, if (a, b, c) is (1, 0, 0), (0, 1, 0), (-1, 1, 0), (1, 1, 0) The conversion values are Cb, Cr, -Cb + Cr, and Cb + Cr. Then, the costs are calculated for these four. The calculation of the cost and the kind of the cost function used have already been described above. Two sets of (a, b, c) having the smallest value among the calculated costs are selected and input to the converter 308. For example, in the above example, if Cb and -Cb + Cr are selected, the conversion unit 308 converts the Cb and -Cb + Cr components. In this case, since the cost is the smallest, the values of the Cb and -Cb + Cr components are the smallest, and therefore the amount of bits required for encoding is small. On the other hand, for macro blocks in intra prediction, (a, b, c) is (-1, 1, 14), (1, 1, -250), (1, 0, 14), (0, 1, 14). ), Etc. In the case of the macro block in the intra prediction, as in the case of the macro block in the interpretation, the cost is calculated for the (a, b, c) coefficient pair and (a, b, c) when the cost is the smallest. Find and encode the color difference component determined by.

Meanwhile, the color difference component converter 330 may be located after the converter 308 and the quantizer 310. That is, reordering and entropy encoding may be performed by calculating a cost using Cb and Cr components that are frequency-converted on a frequency domain rather than a spatial domain.

4 is a reference diagram for explaining calculation of a color difference component transform value according to an embodiment of the present invention.

Referring to FIG. 4, it can be seen that one pixel value is read from the Cb block and the Cr block, and the converted value is calculated by multiplying or adding (a, b, c) values according to Equation 1 described above.

FIG. 5 is a detailed block diagram of the color difference component converter 330 of FIG. 3.

The color difference component converter 330 includes a conversion value calculator 510, a cost calculator 520, and a determiner 530. When the chrominance components Cb and Cr are input, the conversion value calculator 510 calculates the conversion values in all cases that can be made using the given (a, b, c) coefficient set according to Equation (1). The cost calculator 520 calculates a cost for each case calculated. The determination unit 530 selects two cases in which the calculated cost value is the smallest and outputs the converted value at that time.

6 is a flowchart of an encoding method according to an embodiment of the present invention.

When the image data is input, motion estimation (S610) and motion prediction (S620) are performed in the case of inter prediction. In the case of intra prediction, the motion estimation step S610 and the motion prediction step S620 are omitted. Performing motion estimation and motion prediction is as described above with reference to FIG. 3. After the motion prediction is performed, the cost is calculated as described above with reference to FIGS. 4 and 5 for all cases obtainable using the predetermined (a, b, c) coefficients (S630). After calculating the cost, two cases having the smallest value are selected (S640). A transform step (S650), a quantization step (S660), and entropy coding are performed for the selected case (S670). As a result, the color difference components Cb and Cr are encoded in the related art, but the number of bits required for encoding is reduced by encoding the converted color difference components which eliminated the redundancy between the color difference components Cb and Cr in steps S630 and S640.

Meanwhile, the selected (a, b, c) coefficient information is also encoded and transmitted. The selected coefficient information is recorded in the picture header for each macro block to indicate what color difference component is coded and transmitted for each macro block. In the example of interpretation described above, the first and third coefficients are selected from the coefficients (1, 0, 0), (0, 1, 0), (-1, 1, 0), and (1, 1, 0). If so, run length code this information.

In more detail, the selected coefficient information is run length encoded only when the chrominance component block is encoded. In this case, the coefficient information may be used together with the conventional syntax of the chrominance coding block pattern or the CBPC (Coded Block Pattern for Chrominance). When encoding in (run, length) format, the number of bits assigned to a run depends on how many sets you use, and the number of bits assigned to length depends on how many consecutive runs you want to code into one. Different. For example, if the number of sets consists of four types, S1, S2, S3, and S4, A is 2 bits, and if B is 5 bits, one (run, length) is encoded as 7 bits. That is, if S1 comes out 11 times in a row, (S1, 10) can be encoded as "0001010". Since the (a, b, c) coefficient information selected for each macro block is likely to have a value similar to that of the neighboring macro block, the run length encoding method may reduce the number of bits required for encoding. In addition, information indicating whether a color difference block is encoded in units of blocks using a color difference coding block pattern or a CBPC is transmitted.

Since the (a, b, c) coefficient information selected for each macro block is likely to have a value similar to that of the neighboring macro block, the run length encoding method may reduce the number of bits required for encoding.

7 is a block diagram of a decoding apparatus according to an embodiment of the present invention.

The decoding apparatus includes an entropy decoding unit 702, a reordering unit 704, an inverse quantization unit 706, an inverse transform unit 708, a chrominance component inverse transform unit 710, a motion compensator 712, an intra prediction unit ( 714, filter 716, and frame memory 718. When the encoded bit stream is input to the decoding apparatus, the encoded bit stream is input to the color difference component inverse transform unit 708 through entropy decoding, reordering, and inverse transformation. If the inputted data is a luminance component, bypass the color difference component. If the input data is a chrominance component, the chrominance component inverse transform unit 708 finds out by which (a, b, c) coefficients the chrominance component is formed and encoded. Make Cb and Cr ingredients. Since the information on which (a, b, c) chrominance components are encoded and transmitted is also encoded and transmitted according to the run length encoding method, the chrominance component inverse transform unit 710 decodes this information to produce Cb and Cr components. . Meanwhile, as in the case of the encoding apparatus of FIG. 3, the color difference component inverse transform unit 710 may be positioned before the inverse quantization unit 706 and the inverse transform unit 708.

8 is a flowchart of a decoding method according to an embodiment of the present invention.

After the entropy decoding step (S810), the inverse quantization step (S820), and the inverse transform step (S830), the received (a, b, c) coefficient information is decoded, and a combination of Cb and Cr components is found. The reverse conversion thereof finds the Cb and Cr components (S840). And it decodes through motion compensation (S850). In the case of intra prediction, the motion compensation step S850 is omitted.

Hereinafter, an encoding method according to another embodiment of the present invention will be described with reference to FIGS. 9 to 15.

9 is a table illustrating an interprediction mode applied to an embodiment of the present invention. Referring to FIG. 9, the interprediction mode applied to each macroblock is set to five modes of 0 to 4, and as shown in FIG. 12, the interprediction mode is selected in each macroblock unit. do. Cb and Cr blocks are replaced with transform value 1 and transform value 2 according to the selected mode and the table shown in FIG. The relationship between the conversion values and the Cb and Cr values in the respective interprediction modes shown in FIG. 9 is exemplary, and it is possible to selectively add or remove a mode having another relationship.

For example, when the selected interprediction mode for a given macroblock is 0, the transform value 1 becomes the Cb value of the Cb block itself, and the transform value 2 becomes the Cr value of the Cr block itself. In addition, when the selected interprediction mode is 1, the transform value 1 becomes the Cb value itself of the Cb block, and the transform value 2 becomes the value obtained by subtracting the Cr value of the Cr block from the restored Cb value Cb '. The reason for using the restored Cb value and Cr value in the interprediction mode table of FIG. 9 is to recover more accurate Cb and Cr values in the decoding step. Alternatively, it is also possible to use the original Cb and Cr values instead of the restored Cb and Cr values. Here, the restored Cb and Cr values mean values obtained by performing inverse quantization and inverse transformation after performing the transformation and quantization processes, and the original Cb and Cr values mean values before the transformation and quantization processes are performed. do.

FIG. 10 is a table for explaining an inverse inter prediction method for each mode. Referring to FIG. 10, when the interprediction mode of one macroblock is 0, the Cb and Cr values of the macroblock are directly obtained from the transform value 1 and the transform value 2. On the other hand, when the interprediction mode is 1, the Cb value of the macroblock is directly obtained from the transform value 1, while the Cr value is converted value 2 (Cb'-Cr) from the value (Cb ') restored from the transform value 1. Is obtained by subtracting. At this time, the reason why the converted value 2 is subtracted from the restored value of the converted value 1 is that the converted value 2 includes Cb '.

FIG. 11 is a detailed block diagram of another embodiment of the color difference component converter 330 of FIG. 3.

The color difference component converter 330 may include a conversion value calculator 1110, an interprediction mode table storage 1112, a cost calculator 1120, a mode selection and conversion value output unit 1130, and a selection mode storage unit. 1132.

When the color difference components Cb and Cr are input, the conversion value calculator 1110 calculates the conversion value 1 and the conversion value 2 for each interpretation mode stored in the interprediction mode table storage 1112. For example, the conversion value 1 and the conversion value 2 are generated for each mode shown in FIG. In addition, in the present embodiment, the interprediction mode table is stored in the interprediction mode table 1112, which is separate from the conversion value calculation unit 1110, but the interpretation mode table is optionally converted into the conversion value calculation unit 1110. Can be stored in a predetermined place.

The cost calculator 1120 calculates a cost for the converted values calculated for each mode.

The mode selection and conversion value output unit 1130 selects the mode having the smallest calculated cost value, and outputs the conversion values at that time. For example, when mode 1 is selected according to the interprediction mode table shown in FIG. 9, Cb and Cb'-Cr values are output as conversion value 1 and conversion value 2.

The selection mode storage unit 1132 stores mode information for each macroblock selected by the mode selection and conversion value output unit 1130. Mode information for each macroblock stored in the selection mode storage unit 1132 is used to generate an interprediction mode table in picture units shown in FIG. 12. In addition, in this embodiment, the mode information selected in each macroblock unit is stored in the selection mode storage unit 1132, but the information on the selectively selected mode is a predetermined place of the mode selection and conversion value output unit 1132. It is also possible to save to.

The transform values output from the mode selection and transform value output unit 1130 are output to the transform unit 308 and the quantization unit 310, as shown in FIG. 3, to perform a transform and quantization process.

As described above, since the transform value is determined according to the selected mode and the encoding is performed according to the determined transform value, it is necessary to inform the decoder which interprediction mode is selected for each macroblock. Hereinafter, a method for transmitting selected interprediction mode information for each macroblock will be described with reference to FIGS. 12 to 14.

12 shows the selected interprediction mode for each macroblock in one picture. The value at each position has a value of 0, 1, 2, 3, 4, which indicates the interprediction mode applied to the macroblock corresponding to that position. For example, the value '0' at the leftmostmost position indicates that Cb and Cr are replaced, i.e., conversion value 1 = Cb, conversion value 2 = Cr, according to interprediction mode 0 in Table 9 for the corresponding macroblock. . In addition, the values '2 2' corresponding to the next macroblocks at the top are substituted for Cb and Cr according to the interprediction mode 2 in FIG. 9, that is, the conversion value 1 = Cb. , Conversion value 2 = Cb '+ Cr.

13 (a), (b), (c), (d), and (e) are diagrams illustrating interprediction mode values for each macroblock shown in FIG. 12 for each inter prediction mode plane.

FIG. 13A illustrates a mode 0 plane reconfigured to indicate 1 for a macroblock indicating mode 0 and 0 for the remaining macroblocks not indicating mode 0 in the interprediction mode table shown in FIG. 12. plane). For example, among the top values, 1, 4, 5, 7, 8, 10, and 14th values having a 0 value among the interprediction mode values shown in FIG. 12 are set to 1, and the remaining values are Is set to zero.

FIG. 13B shows a mode 1 plane reconfigured to show 1 for a macroblock indicating mode 1 and 0 for the remaining macroblocks not indicating mode 0 in the interprediction mode table shown in FIG. plane). For example, of the top values of the interprediction mode table shown in FIG. 12, the sixth and ninth values having a value of 1 are set to 1, and the remaining values are set to 0. FIG.

FIG. 13C illustrates a mode 2 plane reconfigured to show 1 for a macroblock indicating mode 2 and 0 for the remaining macroblocks not indicating mode 0 in the interprediction mode table shown in FIG. plane). For example, of the top values of the interprediction mode table shown in FIG. 12, 2, 3, 13, 15, 17, 18, 19, 20, 21, and 22nd values having 2 values are set to 1 and , The remaining values are set to zero.

FIG. 13D illustrates a mode 3 plane reconfigured to show 1 for a macroblock indicating mode 3 and 0 for the remaining macroblocks not indicating mode 0 in the interprediction mode table shown in FIG. plane). For example, among the interpretation mode values shown in FIG. 12, since none of the highest values have a value of 3, all are set to zero.

FIG. 13E illustrates a mode 4 plane reconfigured to show 1 for a macroblock indicating mode 4 and 0 for the remaining macroblocks not indicating mode 0 in the interprediction mode table shown in FIG. plane). For example, among the top values of the interprediction mode table shown in FIG. 10, the 11th, 12th, and 16th values having 4 values are set to 1, and the remaining values are set to 0. FIG.

As such, when the interprediction mode table shown in FIG. 12 is divided into the respective mode planes as shown in FIGS. 13A to 13E, the length of 0 run is longer. Lose.

14 (a) to (d) are diagrams for explaining a method of encoding interprediction mode information according to the present invention. 14A to 14D show a mode plane reduction scheme in accordance with the present invention, and the length of one run in each mode plane shown in FIGS. 13A to 13E. Represents a modified mode plane that makes (length of 1 run) longer.

FIG. 14 (a) shows a modified mode 1 in the mode 1 plane of FIG. 13 (b), which deletes '0' values corresponding to macroblocks with a value of 1 in the mode 0 plane of FIG. 13 (a). Show the plane. As shown in Fig. 14 (a), the uppermost 22 bits '0000010010000000000000' of Fig. 13 (b) showing the original Mode 1 plane are 1, 4, 5, The seventh, eighth, tenth, and fourteenth '0' values are transformed into 15-bit '001100000000000', which is removed. The modified mode 1 plane has a reduced amount of bits and longer runs compared to the original mode 1 plane.

FIG. 14 (b) shows a modified mode 2 plane in the mode 2 plane of FIG. 13 (c), with the '0' values deleted corresponding to macroblocks having a value of 1 in the mode 0 plane and the mode 1 plane. Indicates. As shown in FIG. 14 (b), the top 22 bits of FIG. 13 (c) showing the original mode 2 plane '0110000000001010111111' are 1, 4, 5, 7 with a value of 1 in the mode 0 plane. The 8th, 10th, and 14th '0' values and the 6th and 9th '0' values of 1 in the mode 1 plane are transformed to 13 bits of '1100110111111'. The modified mode 2 plane has a reduced amount of bits and longer runs compared to the original mode 2 plane.

FIG. 14 (c) is a modification of '0' values corresponding to macroblocks having a value of 1 in a mode 0 plane, a mode 1 plane, and a mode 2 plane in the mode 3 plane of FIG. 13 (d). Mode 3 plane. As shown in Fig. 14 (c), the top 22 bits '0000000000000000000000' of Fig. 13 (d) showing the original mode 3 plane are 1, 4, 5, 7 with a value of 1 in the mode 0 plane. , 8, 10, 14th '0' value, 2, 3, 13, 15, 17 with value 1 in mode 1 plane, 6th and 9th '0' value, and 1 in mode 2 plane The value '0' at, 18, 19, 20, 21, 22 is transformed into a three-bit '000' that has been removed. The modified mode 3 plane has a reduced bit amount compared to the original mode 3 plane.

14 (d) shows '0' values corresponding to macroblocks having a value of 1 in a mode 0 plane, a mode 1 plane, a mode 2 plane, and a mode 3 plane in the mode 4 plane of FIG. 13E. Represents a modified Mode 4 plane that has been deleted. As shown in Fig. 14 (d), the top 22 bits of Fig. 13 (e) showing the original mode 4 plane '0000000000110001000000' are 1, 4, 5, 7 with a value of 1 in the mode 0 plane. , 8, 10, 14th '0' value, 2, 3, 13, 15, 17 with value 1 in mode 1 plane, 6th and 9th '0' value, and 1 in mode 2 plane The '0' values at, 18, 19, 20, 21, and 22 are transformed into 3 bits of '111' removed. The modified mode 4 plane has a reduced amount of bits and longer runs compared to the original mode 3 plane. In addition, since all of the modified mode 4 planes have a value of 1, coding is not necessary.

In this embodiment, it is possible to reduce the amount of data to be transmitted by performing run length coding on the original mode 0 plane and the modified mode 1-4 planes in which the '1' run is lengthened. It is also possible to optionally perform run length coding on the original mode planes and transmit.

In order to generate the original mode planes of FIGS. 13 (b) to 13 (e), the decoder sequentially restores the mode 4 planes from the mode 1 planes of FIGS. 14 (a) to 14 (d). Further, based on the reconstructed mode planes of FIGS. 13A to 13E, the interprediction mode table of FIG. 12 is restored, and based thereon, the original Cb and Cr values are restored from the converted values. .

FIG. 15 is a flowchart illustrating a method of generating a modified mode plane and an interprediction mode information encoding method illustrated in FIGS. 14A to 14D according to an embodiment of the present invention.

In step 1510, run length coding is performed on the mode 0 plane.

In step 1520, after run length coding is performed on the mode 0 plane, in the mode planes of FIGS. 13 (b) to (e), a value of '0' corresponding to macroblocks having a value of 1 in the mode 0 plane is 1. Remove them, and create the first modified mode planes. Thereafter, run length coding is performed on the first modified mode 1 plane, that is, the modified mode 1 plane shown in FIG.

In step 1530, after run length coding is performed on the modified mode 1 plane, '0' corresponding to macroblocks having a value of 1 in the mode 1 plane is performed in the first, second, and third modified modes. Remove the values and create the second modified mode planes. Thereafter, run length coding is performed on the secondary modified mode 2 plane, that is, the modified mode 2 plane shown in FIG. 14B.

In step 1540, after run length coding is performed on the modified mode 2 plane, '0' values corresponding to macroblocks having a value of 1 in the mode 2 plane are generated in the 2nd modified mode 3 and 4 planes. Remove and create third-order modified mode planes. Then, run length coding is performed on the third-order modified mode 3 plane, that is, the modified mode 3 plane shown in FIG. 14C.

In step 1550, after run length coding is performed on the modified mode 3 plane, in the third-order modified mode 4 plane, values having a value of 1 in the mode 3 plane are removed and a fourth-order modified mode 4 plane is generated. do. Thereafter, run length coding is performed on the fourth-order modified mode 4 plane, that is, the modified mode 3 plane shown in FIG. 14 (d). Optionally, since the values in the last mode plane all have a value of '1', it is possible to restore the original mode planes only with information in the remaining modified modes, even if there is no information in the modified mode 4 planes. It is also possible not to perform separate compression coding for four planes. It is also possible to optionally skip without performing step 1550.

Alternatively, it is also possible to create modified mode planes in a different order than in this embodiment.

After performing steps 1510 to 1550, the run length encoded interprediction information is inserted into the picture header of the bit stream and transmitted.

Hereinafter, a decoding apparatus according to another embodiment of the present invention will be described with reference to FIG. 7.

When the encoded bit stream is input to the decoding apparatus, it is input to the color difference component inverse transform unit 708 through entropy decoding, reordering, and inverse transform. When the input data is a luminance component, the input signal is bypassed. When the input data is a luminance component, the input data is input to the color difference component inverse converter 710.

The interprediction mode determiner (not shown) reconstructs the run length coded mode planes extracted from the picture header of the input bitstream, reconstructs them in order from the mode plane 0, and then, in the picture unit of FIG. 12. The inter-prediction mode table is generated, and the inter-prediction mode applied in units of macroblocks is determined based on the inter-prediction mode table, and input to the chrominance component inverse transform unit 710.

The color difference component inverse transform unit 710 generates Cb and Cr components from the decoded transform values using the determined interprediction mode information.

16 is a flowchart of a decoding method according to an embodiment of the present invention.

After the entropy decoding step S1610, the inverse quantization step S1620, and the inverse transform step S1630, the original mode planes are recovered from the decoded transform mode planes shown in FIG. For example, an interprediction mode table indicating an interprediction mode applied to each macroblock in a picture unit is generated.

From the generated inter-prediction mode table, the inter-prediction mode applied to the macroblock is determined, and Cb and Cr components are calculated by inversely transforming the decoded transform values according to the determined inter-prediction mode (S1640). And it decodes through motion compensation (S1650). In the case of intra prediction, the motion compensation step S1650 is omitted.

On the other hand, the above-described encoding and decoding method can be created by a computer program. Codes and code segments constituting the program can be easily inferred by a computer programmer in the art. In addition, the program is stored in a computer readable media, and read and executed by a computer to implement an encoding and decoding method. The information storage medium includes a magnetic recording medium, an optical recording medium, and a carrier wave medium.

So far I looked at the center of the preferred embodiment for the present invention. Those skilled in the art will appreciate that the present invention can be implemented in a modified form without departing from the essential features of the present invention. Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope will be construed as being included in the present invention.

As described above, according to the present invention, the correlation between the color difference components of the video is found and unnecessary components are removed, thereby increasing the compression ratio of the video. In addition, the number of bits required for encoding is greatly reduced by encoding coefficient information constituting a combination of Cb and Cr components using a run length coding method to find correlation and remove unnecessary components. In addition, by converting the Cb and Cr components for each inter-prediction mode, by splitting the information indicating the mode applied for the conversion into each mode plane and run length coding, there is an effect that more efficient run length coding is possible.

Claims (84)

Cb and Cr values, which are color difference components of a color image, are weighted and combined with predetermined coefficients to form a plurality of transformed values, and two transformed values having the smallest cost calculated by a predetermined cost function among the generated transformed values A color difference component converter for selecting and outputting the color difference component; And And an entropy coding unit for performing entropy encoding on the selected transform value. The method of claim 1, And the chrominance components Cb and Cr have already been transformed and quantized. The method of claim 1, And a transformation and quantization unit configured to perform transformation and quantization on the transform value output from the chrominance component conversion unit if the chrominance components Cb and Cr are values before the transformation and quantization are performed. The method of claim 1, And a motion estimation and compensation unit for performing interprediction. The method of claim 1, The color difference component converting unit calculates a conversion value of the color difference component by ax Cb + bx Cr + c, wherein the a, b, c values are constants, and a plurality of (a, b, c) pairs are predetermined by the user. An encoding device characterized by the above-mentioned. The method of claim 1, And the predetermined cost function comprises RDcost, SAD, SATD, SSA and MAD. The method of claim 1, wherein the color difference component conversion unit A conversion value calculator which calculates a conversion value for all the cases in which the color difference components Cb and Cr are input and weighted and combined with a plurality of (a, b, c) coefficients; A cost calculator configured to calculate a cost with respect to the converted value by a predetermined cost function; And And a determination unit which selects and outputs a transform value in two cases having the smallest value among the calculated cost values. The method of claim 1, wherein the color difference component conversion unit And encoding information about the coefficients (a, b, c) corresponding to two transform values having the smallest cost according to a run length encoding method. (a) Cb and Cr values, which are color difference components of a color image, are weighted and combined with predetermined coefficients to form a plurality of transformed values, and two of the transformed transformed values having the smallest cost calculated by a predetermined cost function Selecting and outputting two conversion values; And (b) an entropy coding step of performing entropy coding on the selected transform value. The method of claim 9, And the chrominance components Cb and Cr have already been transformed and quantized. The method of claim 9, (b0) if the chrominance components Cb and Cr are values before transform and quantization are performed, further comprising a transform and quantization step of performing transform and quantization on the transform value output in step (a). Coding method. The method of claim 9, further comprising: And performing motion estimation and compensation for performing interprediction. The method of claim 9, In the step (a), the conversion value of the color difference component is calculated by ax Cb + bx Cr + c. The a, b, and c values are constants, and a plurality of (a, b, c) pairs are determined by the user. A coding method characterized in that predetermined. The method of claim 9, And the predetermined cost function comprises RDcost, SAD, SATD, SSD and MAD. The method of claim 9, wherein step (a) (a1) calculating conversion values in all cases that may be generated by weighting and combining a plurality of (a, b, c) coefficients when the color difference components Cb and Cr are input; (a2) a cost calculation step of calculating a cost with respect to the converted conversion value by a predetermined cost function; And and (a3) selecting and outputting a transform value in two cases having the smallest value among the calculated cost values. The method of claim 9, wherein step (b) And encoding information about the coefficients (a, b, c) corresponding to the two smallest transformed values determined by the step (a) according to the run length encoding method. An entropy decoding unit for entropy decoding the encoded bit stream; And If the decoded data is a luminance component, bypass it, and in the case of a chrominance component, information about coefficients used to weight and combine the Cb and Cr components is extracted to form an original chrominance component Cb and Cr components. And a color difference component inverse transform unit to be output. The method of claim 17, And an inverse quantization and inverse transform unit for performing inverse quantization and inverse transformation on the entropy decoded data. The method of claim 17, And a motion compensator for performing interprediction. 18. The apparatus of claim 17, wherein the color difference component inverse transform unit 16. A decoding apparatus comprising information on which (a, b, c) coefficient pairs are encoded to calculate Cb and Cr components by extracting transmitted and encoded information according to a run length encoding method. (a) an entropy decoding step of entropy decoding the encoded bit stream; And (b) When the decoded data is a luminance component, bypasses it, and in the case of a chrominance component, extracts information about coefficients used to weight and combine the Cb and Cr components to obtain the chrominance components Cb and Cr components. And generating and outputting. The method of claim 21, (b0) performing inverse quantization and inverse transformation on the entropy decoded data. The method of claim 21, (c) a motion compensation step for performing interprediction. The method of claim 21, wherein step (b) A method of decoding a Cb and Cr component using information transmitted by encoding according to a run length coding method using information on which (a, b, c) coefficient pairs are encoded. In the encoding apparatus of a color image, The color difference component of the color image is converted for each of two or more inter prediction modes, and the values converted for each mode are calculated for each inter prediction mode using a predetermined cost function, and the two or more inters according to the calculation result. A color difference component converter for selecting one of the predicate modes and outputting a converted value of the selected mode; And And an entropy encoder that performs entropy encoding on the output transform value. The encoding method according to claim 25, wherein the selection of the interprediction mode is performed in a predetermined block unit, and the interpretation mode information selected for the predetermined block is encoded in a group unit consisting of a plurality of blocks. Device. 27. The encoding method according to claim 26, wherein a plurality of mode planes in which interprediction mode information of a plurality of blocks in a predetermined group are classified for each mode is generated, and the generated plurality of mode planes are encoded. Device. The encoding apparatus of claim 27, wherein the generated mode plane includes information indicating whether an interprediction mode corresponding to a current mode plane is applied for each of the predetermined blocks. 28. The method of claim 27, wherein the predetermined mode plane has mode information corresponding to the block to which the interprediction mode corresponding to the current mode plane is applied is '1', and the interprediction mode corresponding to the current mode plane is not applied. The encoding apparatus characterized in that the mode information corresponding to the block is obtained by setting to '0'. 27. The method of claim 26, further comprising: generating a plurality of mode planes in which the interprediction mode information of a plurality of blocks in a predetermined group is classified for each mode, and arranging the generated plurality of mode planes in a predetermined order; And encoding the modified mode plane by modifying the information of the next mode plane according to the mode information of the previous mode plane. The method of claim 30, wherein the generated mode plane includes information indicating whether or not an interprediction mode corresponding to a current mode plane has been applied for each of the predetermined blocks, wherein the modification of the information of the mode plane includes: And encoding information on the block to which the interprediction mode of the previous mode plane is applied among the information of the next mode plane based on the information of the previous mode plane. 32. The method of claim 31, wherein the predetermined mode plane has mode information corresponding to a block to which the interprediction mode corresponding to the current mode plane is applied is '1', and the interprediction mode corresponding to the current mode plane is not applied. The encoding apparatus characterized in that the mode information corresponding to the block is obtained by setting to '0'. 33. The method of claim 32, wherein the deleting of the information about the block to which the interprediction mode is applied according to the previous mode is performed by setting the information on the block to which the interprediction mode is applied according to the previous mode is set to '0'. An encoding device. 27. The encoding apparatus of claim 26, wherein the predetermined block is a macroblock, and the group is a picture. The method of claim 25, Wherein the chrominance components are Cb and Cr, and the chrominance components Cb and Cr have already been converted and quantized. The method of claim 25, And a transformation and quantization unit configured to perform transformation and quantization on the transform value output from the chrominance component conversion unit if the chrominance components Cb and Cr are values before the transformation and quantization are performed. The method of claim 25, And a motion estimation and compensation unit for performing interprediction. The method of claim 25, And the predetermined cost function comprises RDcost, SAD, SATD, SSA and MAD. The method of claim 25, wherein the color difference component conversion unit An inter-prediction mode table storage unit for storing an inter-prediction mode table including at least two inter-prediction modes; A conversion value calculator configured to calculate Cb and Cr values, which are color difference components of a color image, for each mode based on the interprediction mode table; And a mode selection unit for selecting an interprediction mode having the smallest cost calculated by a predetermined cost function among the calculated conversion values. The method of claim 25, And a run length encoder configured to perform run length encoding on the selected interprediction mode information. In the encoding method of a color image, The color difference component of the color image is converted for each of two or more interprediction modes, and the values converted for each mode are calculated for each mode using a predetermined cost function, and the two or more interpredictions are calculated according to the calculation result. Selecting one of the modes and outputting a conversion value of the selected mode; And performing entropy encoding on the output transform value. 43. The method of claim 41, wherein the selection of the interprediction mode is performed in units of a predetermined block, and the interpretation mode information selected for the predetermined block is encoded in a group unit consisting of a plurality of blocks. Way. 43. The encoding method of claim 42, wherein a plurality of mode planes in which interprediction mode information of a plurality of blocks in a predetermined group are classified for each mode is generated, and the generated plurality of mode planes are encoded. Way. The encoding method of claim 43, wherein the generated mode plane includes information indicating whether an interprediction mode corresponding to a current mode plane is applied for each of the predetermined blocks. 44. The method of claim 43, wherein the predetermined mode plane has mode information corresponding to a block to which the interprediction mode corresponding to the current mode plane is applied is '1', and the interprediction mode corresponding to the current mode plane is not applied. Encoding method characterized in that the mode information corresponding to the block is obtained by setting to '0'. 43. The method of claim 42, further comprising: generating a plurality of mode planes that classify interprediction mode information for a plurality of blocks in a predetermined group for each mode, and arranging the generated plurality of mode planes in a predetermined order; And encoding the modified mode plane by modifying the information of the next mode plane according to the mode information of the previous mode plane. 47. The method of claim 46, wherein the generated mode plane includes information indicating whether or not an interprediction mode corresponding to a current mode plane is applied for each of the predetermined blocks. And deleting information on a block to which the interprediction mode of the previous mode plane is applied among the information of the next mode plane based on the information of the previous mode plane. 48. The method of claim 47, wherein the predetermined mode plane, the mode information corresponding to the block to which the interprediction mode corresponding to the current mode plane is applied is '1', the interprediction mode corresponding to the current mode plane is not applied. Encoding method characterized in that the mode information corresponding to the block is obtained by setting to '0'. 49. The method of claim 48, wherein the deleting of the information on the block to which the interprediction mode is applied according to the previous mode is performed by setting the information on the block to which the interprediction mode is applied according to the previous mode is set to '0'. An encoding method. 43. The encoding method according to claim 42, wherein the predetermined block is a macroblock and the group is a picture. The method of claim 41, wherein And the chrominance components are Cb and Cr, and the chrominance components Cb and Cr have already been converted and quantized. The method of claim 41, wherein And if the chrominance components Cb and Cr are values before transformation and quantization are performed, performing transformation and quantization on the transform values output from the chrominance component converter. The method of claim 41, wherein And a motion estimation and compensation step for performing interprediction. The method of claim 41, wherein And the predetermined cost function comprises RDcost, SAD, SATD, SSA and MAD. The method of claim 41, wherein the encoding method Calculating conversion values of Cb and Cr, which are color difference components of the color image, for each mode; And selecting an interprediction mode having the smallest cost calculated by a predetermined cost function among the calculated transform values. The method of claim 41, wherein And performing run length coding on the selected interprediction mode information. In the decoding apparatus of the encoded color image, An entropy decoding unit for entropy decoding the input bit stream; And A chrominance component inverse transform unit for restoring an original chrominance component based on interprediction mode information applied to a current block having a predetermined size extracted from the bit stream, The inter-prediction mode information indicates an inter-prediction mode applied to the current block among two or more inter-prediction modes, and wherein the original color difference component is obtained from a transform value corresponding to the inter-prediction mode applied to the current block. Decoding apparatus characterized by. 58. The decoding apparatus of claim 57, wherein the interprediction mode information extracted from the bit stream is a plurality of mode planes generated by classifying interprediction mode information on a plurality of blocks for each mode. The method of claim 58, The generated mode plane includes, for each of the predetermined blocks, information indicating whether an interprediction mode corresponding to a current mode plane is applied. The method of claim 58, In the predetermined mode plane, the mode information corresponding to the block to which the interprediction mode corresponding to the current mode plane is applied is '1', and the mode information corresponding to the block to which the interprediction mode corresponding to the current mode plane is not applied. Is obtained by setting to '0'. The method of claim 58, The interprediction mode information extracted from the bit stream includes a plurality of mode planes generated by classifying interprediction mode information for a plurality of blocks in a predetermined group for each mode, And a modified mode plane generated by modifying information of a next mode plane according to the mode information of the mode plane. 62. The method of claim 61, The generated mode plane includes information indicating whether or not an interprediction mode corresponding to a current mode plane is applied for each of the predetermined blocks, and the modification of the information of the mode plane is based on the information of the previous mode plane. Based on the information on a block to which the interprediction mode of the previous mode plane is applied among the information of the next mode plane, And the decoding apparatus restores the original mode plane by sequentially reconstructing the modified mode planes in a predetermined order. 62. The method of claim 61, In the predetermined mode plane, the mode information corresponding to the block to which the interprediction mode corresponding to the current mode plane is applied is '1', and the mode information corresponding to the block to which the interprediction mode corresponding to the current mode plane is not applied. Is obtained by setting to '0'. The method of claim 63, wherein The deletion of the information on the block to which the interprediction mode is applied according to the previous mode is performed by setting the information on the block to which the interprediction mode is applied according to the previous mode is set to '0'. The method of claim 58, The block having a predetermined size is a macroblock, and the mode plane includes interprediction mode information for a macroblock in a picture unit. The method of claim 57, The chrominance component is Cb, Cr. The method of claim 57, And an inverse quantization and inverse transform unit for performing inverse quantization and inverse transformation on the entropy decoded data. The method of claim 57, And a motion compensator for performing interprediction. 59. The decoding apparatus of claim 58, wherein the decoding apparatus extracts interprediction mode information encoded and transmitted according to a run length coding method, and calculates a color difference component based on the extracted information. In the decoding method of the encoded color image, Entropy decoding the input bit stream; Restoring an original chrominance component based on the interprediction mode information applied to the current block of a predetermined size extracted from the bit stream, The inter-prediction mode information indicates an inter-prediction mode applied to the current block among two or more inter-prediction modes, and wherein the original color difference component is obtained from a transform value corresponding to the inter-prediction mode applied to the current block. A decoding method characterized by the above-mentioned. The method of claim 70, And the interprediction mode information extracted from the bit stream is a plurality of mode planes generated by classifying interprediction mode information of a plurality of blocks for each mode. The method of claim 71, wherein The generated mode plane includes, for each of the predetermined blocks, information indicating whether an interprediction mode corresponding to a current mode plane is applied. The method of claim 71, wherein In the predetermined mode plane, the mode information corresponding to the block to which the interprediction mode corresponding to the current mode plane is applied is '1', and the mode information corresponding to the block to which the interprediction mode corresponding to the current mode plane is not applied. Is obtained by setting to '0'. The method of claim 71, wherein The interprediction mode information extracted from the bit stream includes a plurality of mode planes generated by classifying interprediction mode information for a plurality of blocks in a predetermined group for each mode, And a modified mode plane generated by modifying information of a next mode plane according to the mode information of the mode plane. The method of claim 74, wherein The generated mode plane includes information indicating whether or not an interprediction mode corresponding to a current mode plane is applied for each of the predetermined blocks, and the modification of the information of the mode plane is based on the information of the previous mode plane. Based on the information on a block to which the interprediction mode of the previous mode plane is applied among the information of the next mode plane, And the decoding apparatus restores the original mode plane by sequentially reconstructing the modified mode planes in a predetermined order. 76. The method of claim 75, In the predetermined mode plane, the mode information corresponding to the block to which the interprediction mode corresponding to the current mode plane is applied is '1', and the mode information corresponding to the block to which the interprediction mode corresponding to the current mode plane is not applied. Is obtained by setting to '0'. 77. The method of claim 76, The deletion of the information on the block to which the interprediction mode is applied according to the previous mode is performed by setting the information on the block to which the interprediction mode is applied according to the previous mode is set to '0'. The method of claim 71, wherein The predetermined size block is a macroblock, and the mode plane includes interprediction mode information for a macroblock of a picture unit. The method of claim 70, The color difference component is a decoding method characterized in that the Cb, Cr. The method of claim 70, And performing inverse quantization and inverse transformation on the entropy decoded data. The method of claim 70, And a motion compensation step for performing interprediction. 72. The decoding method of claim 71, wherein the decoding method extracts the interprediction mode information encoded and transmitted according to the run length coding method, and calculates a color difference component based on the extracted information. A computer-readable recording medium having recorded thereon a program for executing the coding method according to any one of claims 9 to 16 and 41 to 56 on a computer. A computer-readable recording medium having recorded thereon a program for executing the decoding method according to any one of claims 21 to 24 and 70 to 82.

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