KR101365566B1 - Method and apparatus for encoding and decoding image - Google Patents

Abstract

An image encoding method and apparatus according to the present invention may encode a luminance block according to a preset encoding mode for each luminance block, encode a chrominance block in consideration of encoding modes of one or more luminance blocks corresponding to the chrominance block, The image decoding method and apparatus according to the present invention decode a luminance block according to a decoding mode preset for each luminance block, and decode a chrominance block in consideration of decoding modes of one or more of the luminance blocks corresponding to the chrominance block. According to the present invention, when the image to be compressed (or reconstructed) is expressed separately from the luminance component and the chrominance component, the present invention provides various methods of determining an encoding mode (or a decoding mode) of the chrominance component. Color difference when a motion vector is taken into account when coding (or decoding) a color difference component Minutes, has the effect of providing a variety of ways of determining the motion vector of the image.

Description

Image encoding and decoding method and apparatus {Method and apparatus for encoding and decoding image}

1 is a block diagram for explaining an image encoding and decoding process.

FIG. 2 is a block diagram of an embodiment 110A for explaining the encoding unit 110 shown in FIG.

FIG. 3 is a block diagram of an embodiment 120A for explaining the decoding unit 120 shown in FIG.

4A to 4C are views for explaining a 4: 2: 0 format, a 4: 2: 2 format, and a 4: 4: 4 format.

5 is a block diagram for explaining an image encoding apparatus according to the present invention.

FIG. 6 is a block diagram of an embodiment 514A for describing the second encoder 514 illustrated in FIG. 5.

7 to 9 are diagrams for describing motion information.

10 is a block diagram illustrating an image decoding apparatus according to the present invention.

FIG. 11 is a block diagram of an embodiment 1040A for describing the second decoder 1040 illustrated in FIG. 10.

FIG. 12 is a diagram for explaining a principle of encoding / decoding an image using a 1MV scheme.

13 is a flowchart of the first embodiment for explaining a video encoding method according to the present invention.

14 is a flowchart of a first embodiment for explaining a video decoding method according to the present invention.

15 to 17 are diagrams of a first embodiment for explaining a principle of encoding / decoding an image using a 4MV scheme.

18 is a flowchart of a second embodiment for explaining a video encoding method according to the present invention.

19 is a flowchart of a second embodiment for explaining a video decoding method according to the present invention.

20 is a diagram for describing a principle of encoding / decoding an image using a 4MV scheme.

21 is a flowchart of the third embodiment for explaining a video encoding method according to the present invention.

22 is a flowchart of a third embodiment for explaining a video decoding method according to the present invention.

FIG. 23 is a diagram for describing a principle of encoding / decoding an image using a 4MV scheme.

24 is a flowchart of the fourth embodiment for explaining a video encoding method according to the present invention.

25 is a flowchart of the fourth embodiment for explaining a video decoding method according to the present invention.

FIG. 26 is a diagram for explaining a principle of encoding / decoding an image using a 4MV scheme.

The present invention relates to image compression and decompression, and more particularly, to an image encoding and decoding method and apparatus for compressing and decompressing an image composed of a luminance block and a color difference block.

If the image to be compressed is an image expressed in an RGB (R: Red, G: Green, B: Blue) color space, the resolutions of the three color (R, G, B) components of the image are generally the same. This is because the three colors are equally important.

On the other hand, a human visual system (HVS) is more sensitive to luminance (luma) than chroma. By using this point, an image can be expressed by expressing the luminance component with a resolution higher than that of the color difference component.

As described above, in compressing and restoring an image in which the luminance component and the chrominance component are expressed separately, it is a problem to encode (or decode) each of the luminance component and the chrominance component according to an encoding mode (or decoding mode). . In this regard, when a motion vector is considered in encoding (or decoding) a luminance component and a chrominance component, how to determine the motion vector under consideration is also a problem.

A first aspect of the present invention is to provide an image decoding method and apparatus for decoding a chrominance block according to a decoding mode determined in consideration of decoding modes of one or more luminance blocks.

Another object of the present invention is to provide an image encoding method and apparatus for encoding a color difference block according to an encoding mode determined by considering encoding modes of one or more luminance blocks.

Another object of the present invention is to provide an image decoding method and apparatus for decoding a chrominance block in consideration of a motion vector determined by considering motion vectors of one or more luminance blocks.

A fourth aspect of the present invention is to provide an image encoding method and apparatus for encoding a chrominance block in consideration of a motion vector determined by considering motion vectors of one or more luminance blocks.

In order to achieve the first technical problem, an image decoding method according to the present invention includes: decoding a luminance block according to a decoding mode preset for each luminance block; And decoding the chrominance block in consideration of decoding modes of one or more of the luminance blocks corresponding to the chrominance block.

In order to achieve the first technical problem, an image decoding apparatus according to the present invention includes: a first decoding unit decoding a luminance block according to a decoding mode preset for each luminance block; And a second decoder which decodes a color difference block in consideration of decoding modes of one or more of the luminance blocks corresponding to the color difference block.

In order to achieve the second technical problem, an image encoding method according to the present invention includes: encoding a luminance block according to a coding mode preset for each luminance block; And encoding the chrominance block in consideration of encoding modes of one or more of the luminance blocks corresponding to the chrominance block.

In order to achieve the second technical problem, an image encoding apparatus according to the present invention includes: a first encoding unit encoding a luminance block according to a coding mode preset for each luminance block; And a second encoder which encodes a color difference block in consideration of encoding modes of one or more luminance blocks corresponding to the color difference block.

According to an aspect of the present invention, there is provided a method of decoding an image, comprising: determining a motion vector of a chrominance block in consideration of motion vectors of one or more luminance blocks corresponding to the chrominance block; And decoding the chrominance block in consideration of the determined motion vector.

In order to achieve the third technical problem, an image decoding apparatus according to the present invention includes: a motion vector determiner configured to determine a motion vector of a color difference block in consideration of motion vectors of one or more luminance blocks corresponding to the color difference block; And a color difference component decoder which decodes the color difference block in consideration of the determined motion vector.

According to an aspect of the present invention, there is provided a method of encoding an image, the method comprising: determining a motion vector of a chrominance block by considering motion vectors of one or more luminance blocks corresponding to the chrominance block; And encoding the chrominance block in consideration of the determined motion vector.

In order to achieve the fourth technical problem, an image encoding apparatus according to the present invention includes: a motion vector determiner configured to determine a motion vector of a chrominance block in consideration of motion vectors of one or more luminance blocks corresponding to the chrominance block; And a color difference component encoder which encodes the color difference block in consideration of the determined motion vector.

For a better understanding of the present invention, operational advantages of the present invention and the objects achieved by the practice of the present invention, reference should be made to the accompanying drawings which illustrate preferred embodiments of the present invention and to the description of the attached drawings.

Hereinafter, a video encoding and decoding method and apparatus according to the present invention will be described with reference to the accompanying drawings.

FIG. 1 is a block diagram for explaining an image encoding and decoding process in detail, and includes a coding unit 110 and a decoding unit 120. FIG.

The encoding unit 110 encodes the image input through the input terminal IN 1 to generate a bitstream, and transmits the bitstream to the decoding unit 120. Here, it is preferable that the image is a representation of a luminance component and a color difference component rather than being expressed in an RGB color space. In this case, the image of the luminance component is composed of one or more luminance blocks, and the image of the chrominance component is composed of one or more color difference blocks. On the other hand, the image is preferably composed of a plurality of frames having temporal posterior relation.

The decoding unit 120 decodes the bit stream transmitted from the encoding unit 110 to restore the image and outputs the decoded image through the output terminal OUT 1. If the encoding unit 110 compresses the image losslessly, the reconstructed image is completely identical to the image input through the input terminal IN 1. Similarly, if the encoding unit 110 compresses the image lossy, the reconstructed image can be approximated to the image input through the input terminal IN 1, but can not be completely the same.

Such encoding and decoding can be performed in units of macroblocks. That is, the image can be compressed in units of macroblocks, and can be restored in units of macroblocks. Here, the macroblock includes one or more luminance blocks and one or more color difference blocks.

FIG. 2 is a block diagram of an embodiment 110A for describing the encoder 110 illustrated in FIG. 1, which includes a motion estimator 212, a reference image storage unit 214, a motion compensator 216, To the spatial transform unit 218, the quantizer 220, the inverse quantizer 222, the inverse spatial transform unit 224, the rearrangement unit 226, the zero encoder 228, and the entropy encoder 230. Can be done.

The encoding unit 110 may encode an image input through the input terminal IN 2 in an inter mode or an intra mode. The input terminal IN 2 is the same as the input terminal IN 1 shown in FIG.

Here, the inter mode refers to a method of encoding (or decoding) using motion compensation, and the intra mode refers to a method of encoding (or decoding) without using motion compensation.

If the encoding unit 110 encodes an image in the inter mode, both the motion estimation unit 212 and the entropy encoding unit 230 operate. On the other hand, if the encoding unit 110 encodes the image into the intra mode, the motion estimation unit 212, the motion compensation unit 216, the inverse quantization unit 222, and the inverse spatial conversion unit 224 do not operate .

The operation of the encoding unit 110 operating in the inter mode will be described below. For convenience of explanation, the operation of the encoding unit 110 that performs block-based motion compensation will be described.

The motion estimation unit 212 refers to a block of interest (m * n blocks of interest, m and n are natural numbers, and m * n blocks are m rows of pixels arranged in n columns) ) In the reference frame, which is the closest matching m * n block. Blocks found through this process are called prediction blocks.

Herein, the block of interest means a block to be coded at present, and the reference frame means one or more previously coded frames. The reference frame is stored in the reference image storage unit 214, and the motion estimation unit 212 reads and uses the reference frame stored in the reference image storage unit 214.

The motion compensation unit 216 generates an error block by subtracting the prediction block from the interest block. Meanwhile, the motion compensation unit 216 also generates a motion vector (MV), which is a vector indicating a position relative to the prediction block of the block of interest.

As described above, the interest block, the prediction block, and the error block are all m * n blocks and are made up of pixel values.

The spatial transform unit 218 transforms this 'pixel value' into 'frequency'. Specifically, the spatial transform unit 218 closes the data constituting the error block in a low frequency band.

More specifically, the spatial transform unit 218 may perform DCT (Discrete Cosine Transform). Here, the concrete concept of DCT is disclosed in detail in "Discrete Cosine Transform ", published in 1990 by Academic Press, in cooperation with K. R. Rao and P. Yip. In this case, the spatial transform unit 218 transforms m * n pixel values included in the error block into m * n DCT coefficients.

The quantization unit 220 quantizes the DCT coefficients generated in the spatial transform unit 218. At this time, the quantization unit 220 may perform linear quantization or non-linear quantization. In particular, the quantization unit 220 may perform non-linear quantization so that non-zero DCT coefficients close to zero can be made zero.

The inverse quantizer 222 and the inverse spatial transform unit 224 operate to produce a reference frame to be used in encoding a block of interest to be encoded next.

The inverse quantization unit 222 inversely quantizes the quantized result in the quantization unit 220 and the inverse spatial conversion unit 224 performs an inverse spatial transform (e.g., an inverse quantization) on the inverse quantized result in the inverse quantization unit 222, Inverse DCT). Thus, the inverse spatial transform unit 224 generates an error block.

In this case, the generated error block is added to the prediction block found in the motion estimation unit 212 to restore the 'interest block', and the restored interest block is stored in the reference image storage unit 214 as a part of the reference frame. / RTI >

The reordering unit 226 scans and rearranges the quantized results zig-zag in the quantization unit 220. The zero encoder 228 may perform run-level (RL) encoding. More specifically, the zero-encoding unit 228 can represent the rearranged values more concisely. More specifically, the zero-encoding unit 228 can express the rearranged values as a sequence of (run, level). Here, run means the number of zeros before the non-zero rearranged value, and level means the non-zero rearranged value.

The entropy encoding unit 230 entropy-codes the result of the encoding performed by the zero encoding unit 228. The entropy encoding unit 230 also entropy-encodes the motion vector generated by the motion compensation unit 216. As described above, the entropy-encoded results in the entropy encoding unit 230 are output through the output terminal OUT2 as one bitstream.

Meanwhile, the operation of the encoder 110 operating in the intra mode will be described below.

The spatial conversion unit 218 converts the pixel value of the image input through the input terminal IN 2 into a frequency. Specifically, the spatial transform unit 218 closes the data that form the image in a low frequency band. More specifically, the spatial transform unit 218 can perform DCT.

In this case, the quantization unit 220 quantizes DCT coefficients generated in the spatial transform unit 218. At this time, the quantization unit 220 may perform linear quantization or non-linear quantization. In particular, the quantization unit 220 may perform non-linear quantization so that non-zero DCT coefficients close to zero can be made zero.

The reordering unit 226 scans and rearranges the quantized results zig-zag in the quantization unit 220. The zero encoding unit 228 can perform RL (run-level) encoding. More specifically, the zero-encoding unit 228 can represent the rearranged values more concisely. More specifically, the zero-encoding unit 228 can express the rearranged values as a sequence of (run, level). Here, run means the number of zeros before the non-zero rearranged value, and level means the non-zero rearranged value.

The entropy encoding unit 230 entropy-codes the result of the encoding performed by the zero encoding unit 228. As described above, the entropy-encoded results in the entropy encoding unit 230 are output through the output terminal OUT2 as one bitstream.

FIG. 3 is a block diagram of an embodiment 120A for describing the decoder 120 illustrated in FIG. 1, which includes an entropy decoder 312, a zero decoder 314, an inverse rearranger 316, and an inverse. A quantization unit 318, an inverse spatial transform unit 320, a motion estimation unit 322, and a reference image storage unit 324 may be provided.

The decoding unit 120 may decode the bit stream input through the input terminal IN 3 into an inter mode or an intra mode. The bit stream input through the input terminal IN 3 may be a bit stream output through the output terminal OUT 2 shown in FIG.

If the decoding unit 120 decodes the bit stream into the inter mode, both the entropy decoding unit 312 and the reference image storing unit 324 operate. On the other hand, if the decoding unit 120 decodes the bitstream into the intra mode, the motion estimation unit 322 does not operate.

The operation of the decoding unit 120 operating in the inter mode will be described below.

The entropy decoding unit 312 entropy-decodes the bitstream input through the input terminal IN 3. Accordingly, the entropy decoding unit 312 extracts the RL-encoded result from the zero encoding unit 228 and the motion vector generated by the motion compensation unit 216 from the bit stream input through the input terminal IN 3 .

The zero decoding unit 314 performs RL decoding and the inverse rearranging unit 316 generates quantized results in the quantization unit 220. [

The inverse quantization unit 318 dequantizes the result of the quantization unit 220 inputted from the inverse rearrangement unit 316 and the inverse spatial transform unit 320 dequantizes the result generated by the inverse quantization unit 318, Performs an inverse spatial transform (e. G., Inverse DCT) on the result. Thus, the inverse spatial transform unit 318 generates an error block.

The motion estimation unit 322 searches for a prediction block in a reference frame stored in the reference image storage unit 324 using the motion vector extracted by the entropy decoding unit 312.

In this case, the error block generated by the inverse spatial transform unit 318 and the prediction block found by the motion estimation unit 322 are added to restore the 'interest block', and the restored interest block is output to the output terminal OUT 3 Lt; / RTI > The restored interest block is stored in the reference image storage unit 324 as a part of the reference frame.

The operation of the decoding unit 120 operating in the intra mode will be described below.

The entropy decoding unit 312 extracts the RL-encoded result from the zero-encoding unit 228 from the bitstream input through the input terminal IN 3.

The zero decoding unit 314 performs RL decoding and the inverse rearranging unit 316 generates quantized results in the quantization unit 220. [

The inverse quantization unit 318 dequantizes the result of the quantization unit 220 inputted from the inverse rearrangement unit 316 and the inverse spatial transform unit 320 dequantizes the result generated by the inverse quantization unit 318, Performs an inverse spatial transform (e. G., Inverse DCT) on the result. Thus, the inverse spatial transform unit 318 restores the image and outputs the reconstructed image through the output terminal OUT4. And the reconstructed image may be stored in the reference image storage unit 324.

4A to 4C are views for explaining a 4: 2: 0 format, a 4: 2: 2 format, and a 4: 4: 4 format.

4A shows a macroblock of an image having a 4: 2: 0 format. More specifically, a macroblock of an image having a 4: 2: 0 format may include four luminance blocks Y, one blue chrominance block Cb, and one red chrominance block Cr. Each of the luminance block Y, the blue color difference block Cb or the red color difference block Cr is 8 * 8 block. That is, eight pixels are arranged in eight columns in each of the luminance block Y, the blue color difference block Cb, and the red color difference block Cr, so that there are a total of 64 samples. As shown in Fig. 4A, numerals (0, 1, 2, 3, 4, or 5) indicated for each block are identification symbols of each block.

4B shows a macroblock of an image having a 4: 2: 2 format. More specifically, a macro block of an image having a 4: 2: 2 format may be composed of four luminance blocks Y, two blue chrominance blocks Cb, and two red chrominance blocks Cr. Each luminance block (Y), each blue color difference block (Cb), or each red color difference block (Cr) is 8 * 8 block. That is, eight pixels are arranged in eight rows in each of the luminance blocks Y, the blue chrominance blocks Cb, and the red chrominance blocks Cr, so that a total of 64 samples exist . As shown in Fig. 4B, numerals (0, 1, 2, 3, 4, 5, 6, or 7) indicated for each block are identification symbols of each block.

4C shows a macroblock of an image having a 4: 4: 4 format. More specifically, the macro block of the image having the 4: 4: 4 format may be composed of four luminance blocks Y, four blue chrominance blocks Cb, and four red chrominance blocks Cr. Each luminance block (Y), each blue color difference block (Cb), or each red color difference block (Cr) is 8 * 8 block. That is, eight pixels are arranged in eight columns in each luminance block Y, each blue chrominance block Cb, or each red chrominance block Cr, so that a total of 64 samples exist. . As shown in FIG. 4C, the numbers (0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, or 11) indicated for each block are identification symbols of each block.

FIG. 5 is a block diagram illustrating a video encoding apparatus according to the present invention, and includes a first encoder 512, a second encoder 514, a third encoder 516, and a formatter 518. It may include.

Here, each of the first encoding unit 512 and the second encoding unit 514 is implemented in the motion estimation unit 212 to the entropy encoding unit 230 shown in FIG.

Specifically, the first encoding unit 512 means a 'motion estimation unit 212 to an entropy encoding unit 230' that encodes the luminance block Y input through the input terminal IN 2. Likewise, the second encoding unit 514 means a 'motion estimation unit 212 to an entropy encoding unit 230' for encoding the color difference block Cb or Cr inputted through the input terminal IN 2.

The first encoding unit 512 encodes the luminance block Y included in the image input through the input terminal IN 4 according to a predetermined encoding mode for each luminance block. Here, the input terminal IN 4 is the same as the input terminal IN 2 shown in FIG.

According to the first embodiment of the present invention, the second encoding unit 514 converts the color difference block Cb or Cr included in the image input through the input terminal IN 4 into a predetermined encoding mode for each luminance block Y Encoding mode of a majority of ". In this case, it is preferable that the image has one of a 4: 2: 0 format, a 4: 2: 2 format, and a 4: 4: 4 format.

According to the second embodiment of the present invention, the second encoding unit 514 encodes the color difference block (Cb or Cr) included in the image input through the input terminal IN 4 according to a preset encoding mode for each color difference block . In this case, it is preferable that the image has one of a 4: 2: 0 format, a 4: 2: 2 format, and a 4: 4: 4 format.

The coding mode in which the color difference block is encoded for each color difference block (Cb or Cr) included in the image is preset before the image is input to the motion estimation unit 212 or the motion compensation unit 216 desirable.

According to the third embodiment of the present invention, the second encoding unit 514 converts the chrominance block Cb or Cr included in the image input through the input terminal IN4 into a signal having the same phase as that of the chrominance block Coding mode of the luminance block '. In this case, the image is preferably a 4: 2: 2 format or a 4: 4: 4 format.

According to the fourth embodiment of the present invention, the second encoder 514 sets the chrominance block Cb or Cr included in the image input through the input terminal IN 4 to have the same phase as that of the chrominance block. Encoding is performed taking into consideration the encoding modes of the plurality of luminance blocks including the luminance block. For example, the second encoder 514 encodes the color difference block into an encoding mode of a luminance block having a phase equal to the phase of the color difference block and a luminance block adjacent to the luminance block having a phase identical to the phase of the color difference block. Encoding may be performed according to an encoding mode determined according to whether the modes' match. In this case, if the "coding mode of the luminance block having the same phase as the phase of the chrominance block" and the "coding mode of the luminance block adjacent to the luminance block having the same phase as the phase of the chrominance block" match, the second encoding unit ( 514 may encode the chrominance block according to the encoding mode of the luminance block having the same phase as that of the chrominance block. In contrast, if the encoding mode of the luminance block having the same phase as the phase of the chrominance block and the encoding mode of the luminance block adjacent to the luminance block having the same phase as the phase of the chrominance block are different from each other, the second encoder ( The 514 may encode the color difference block according to a predetermined encoding mode (eg, an inter mode). In the case of the fourth embodiment of the present invention, the video is preferably in 4: 2: 2 format.

According to the first, third, or fourth embodiments of the present invention, in which encoding mode the luminance block is encoded for each luminance block Y included in the image, the image is input terminal IN. It is preferable that it is already set when it is input to 4. Likewise, according to the second embodiment of the present invention, for each luminance block Y included in an image, which encoding mode the luminance block is to be coded and for each blue color difference block Cb included in the image Which encoding mode the blue chrominance block is to be coded and in which encoding mode the red chrominance block is encoded for each red chrominance block Cr included in the image is input to the input terminal IN 4 It is preferable that it is already set. As a result, both the video and the mode information are input to the input terminal IN 4. Here, the mode information indicates an encoding mode (or a decoding mode), and an encoding mode (or decoding mode) may be an inter mode or an intra mode.

The motion information generating unit (not shown) is preferably provided in the image encoding apparatus according to the present invention, and the motion information generating unit generates motion information. In detail, the motion information generator (not shown) according to any one of the first to fourth embodiments of the present invention may perform motion information for each of at least some luminance blocks encoded by the first encoder 512. It is preferable to generate. In addition, the motion information generator (not shown) according to the second embodiment of the present invention preferably generates motion information for each of at least some color difference blocks encoded by the second encoder 514.

The motion information includes mode information and CBP (Coded Block Pattern). If the mode information indicates the inter mode, the motion information also includes information on the motion vector.

CBP indicates whether there is a non-zero value in the quantized result. In order to generate CBP, a CBP generator (not shown) may be provided in the image encoding apparatus according to the present invention. Each time the operation of the quantization unit 220 is completed for a certain block, a CBP generation unit (not shown) checks whether a non-zero value exists in the quantized result. If it is checked that a non-zero value exists, 1 is generated as the CBP of the block, and when it is checked that the non-zero value does not exist, 0 is generated as CBP of the block.

The motion information generating unit (not shown) generates motion information including 'mode information input through the input terminal IN 4' and CBP 'generated by a CBP generating unit (not shown).

The third encoder 516 encodes the motion information generated by the motion information generator (not shown).

The formatter 518 may be implemented in the entropy encoder 230 shown in FIG. 2.

The formatter 518 generates a bit stream by integrating the results encoded by the first encoder 512, the results encoded by the second encoder 514, and the results encoded by the third encoder 516. The generated bitstream is output through the output terminal OUT5. The output terminal OUT 5 is the same as the output terminal OUT 2 shown in Fig.

FIG. 6 is a block diagram of an embodiment 514A for describing the second encoder 514 according to the first, third, or fourth embodiments of the present invention. 610 and a chrominance component encoder 620. Referring to FIG. 6, it will be assumed that the color difference block to be encoded by the second encoder 514 is encoded according to the inter mode.

The motion vector determiner 610 determines the motion vector of the color difference block Cb or Cr included in the image input through the input terminal IN 5 in consideration of the motion vectors of one or more luminance blocks corresponding to the color difference block. . For example, the motion vector determiner 610 may determine a motion vector of the chrominance block as the motion vector of the luminance block adjacent to the luminance block having the same phase as the phase of the chrominance block and the luminance having the same phase as the phase of the chrominance block. It may be determined considering the motion vector of the block. Assuming that all eight blocks shown in FIG. 4B are encoded in the inter mode, the motion vector determiner 610 exemplarily illustrates the operation of the motion vector determiner 610 using the bar illustrated in FIG. 4B. Motion vectors of each of the four (4th, 5th, 6th, and 7th blocks) may be calculated according to Equation 1 below.

MV4_x = MV5_x = {MV0_x + MV1_x} / 4

MV4_y = MV5_y = {MV0_y + MV1_y} / 2

MV6_x = MV7_x = {MV2_x + MV3_x} / 4

MV6_y = MV7_y = {MV2_y + MV3_y} / 2

Here, MV0_x, MV1_x, MV2_x, MV3_x, MV4_x, MV5_x, MV6_x, MV7_x are each a horizontal component of the motion vector of the 0th block, a horizontal component of the motion vector of the 1st block, a horizontal component of the motion vector of the 2nd block, and 3 The horizontal component of the motion vector of the first block, the horizontal component of the motion vector of the fourth block, the horizontal component of the motion vector of the fifth block, the horizontal component of the motion vector of the sixth block, and the horizontal component of the motion vector of the seventh block it means.

Similarly, MV0_y, MV1_y, MV2_y, MV3_y, MV4_y, MV5_y, MV6_y, MV7_y are each the vertical component of the motion vector of the 0th block, the vertical component of the motion vector of the 1st block, the vertical component of the motion vector of the 2nd block, 3 Each of the vertical component of the motion vector of the first block, the vertical component of the motion vector of the fourth block, the vertical component of the motion vector of the fifth block, the vertical component of the motion vector of the sixth block, and the vertical component of the motion vector of the seventh block it means.

In this specification, the horizontal direction means a direction from the 0th block (or 1st block) to the 1st block (or 0th block), and the vertical component is the 2nd in the 0th block (or 2nd block). It means the direction to a block (or 0th block). In addition, a horizontal component means a component in a horizontal direction, and a vertical component means a component in a vertical direction.

The color difference component encoder 620 encodes the color difference block included in the image input through the input terminal IN 5 in consideration of the determined motion vector, and outputs the encoded result to the formatter 518 through the output terminal OUT 6. . The input terminal IN 5 may be the same as the input terminal IN 4 described above.

7 to 9 are diagrams for describing motion information (MI). The motion information may be present in every block as shown in FIGS. 7 to 9, and may be present in each of some blocks, as shown in FIGS. 7 to 9.

FIG. 7A illustrates a macroblock of an image having a 4: 2: 0 format shown in FIG. 4A. For convenience of description, reference numerals 712, 714, 716, 718, 720, and 730 are respectively named 1, 2, 3, 4, 5, 6th blocks.

FIG. 7B illustrates an example in which the motion information of the macroblock shown in FIG. 7A is represented by the bitstream 740. Here, MI (t) (t is an integer of 1? T? 6) means motion information generated by a motion information generating unit (not shown) for the t-th block.

FIG. 8A illustrates a macroblock of an image having a 4: 2: 2 format shown in FIG. 4B. For convenience of description, reference numerals 812, 814, 816, 818, 820, 822, 824, and 826 are respectively named 1, 2, 3, 4, 5, 6, 7, and 8th blocks.

FIG. 8B illustrates an example in which the motion information of the macroblock shown in FIG. 8A is represented by the bitstream 830. Here, MI (u) (where u is an integer of 1? U? 8) denotes motion information generated by a motion information generating unit (not shown) for the u-th block.

FIG. 9A illustrates a macroblock of an image having a 4: 4: 4 format shown in FIG. 4C. For convenience of explanation, reference numerals 912, 914, 916, 918, 920, 922, 924, 926, 928, 930, 932, 934 are each 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 The 11th and 12th blocks are called.

FIG. 9B illustrates an example in which the motion information of the macroblock illustrated in FIG. 9A is represented by the bitstream 940. Here, MI (v) (where v is an integer satisfying 1? V? 12) means motion information generated by the motion information generating unit (not shown) for the vth block.

FIG. 10 is a block diagram illustrating an image decoding apparatus according to the present invention, and includes a deformatter 1010, a third decoder 1020, a first decoder 1030, and a second decoder 1040. It can be made of).

The deformatter 1010 extracts motion information, encoded luminance blocks, and encoded color difference blocks from the bitstream input through the input terminal IN6. The input terminal IN 5 may be the same as the input terminal IN 3 described above.

The third decoder 1020 decodes the extracted motion information.

Each of the first decoder 1030 and the second encoder 930 is implemented in the entropy decoder 312 to the reference image storage 324 illustrated in FIG. 3. In detail, the first decoder 1030 refers to an entropy decoding unit 312 to a reference image storage unit 324 that decodes the luminance block Y. Similarly, the second decoder 1040 refers to the entropy decoder 312 to the reference image storage 324 which decodes the chrominance block Cb or Cr.

The first decoder 1030 decodes the luminance block Y according to a decoding mode preset for each luminance block. Specifically, the preset decoding mode may already appear in the bitstream input through the input terminal IN5.

Therefore, the first decoder 1030 checks whether motion information of the luminance block to be decoded exists in the motion information decoded by the third decoder 1020.

If it is checked that the motion information of the luminance block to be decoded does not exist in the motion information decoded by the third decoder 1020, the first decoder 1030 decodes the luminance block to be decoded in a constant decoding mode. do. At this time, the constant decoding mode may be an inter mode or an intra mode.

On the other hand, if it is checked that the motion information of the luminance block to be decoded is present in the motion information decoded by the third decoder 1020, the first decoder 1030 may appear in the mode information included in the decoded motion information. Analyze whether the decoding mode is inter mode or intra mode. In this case, the first decoder 1030 decodes the luminance block to be decoded according to the analyzed decoding mode.

According to the first embodiment of the present invention, the second decoder 1040 sets the chrominance block Cb or Cr to a decoding mode of a majority of decoding modes preset for each luminance block Y. Decrypt In this case, it is preferable that the image has one of a 4: 2: 0 format, a 4: 2: 2 format, and a 4: 4: 4 format.

According to the second embodiment of the present invention, the second decoder 1040 decodes the color difference block Cb or Cr according to a decoding mode preset for each color difference block. In this case, it is preferable that the image has one of a 4: 2: 0 format, a 4: 2: 2 format, and a 4: 4: 4 format.

Specifically, the preset decoding mode may already appear in the bitstream input through the input terminal IN5.

Therefore, the second decoder 1040 checks whether motion information of the color difference block to be decoded is present in the motion information decoded by the third decoder 1020.

If it is checked that the motion information of the color difference block to be decoded does not exist in the motion information decoded by the third decoder 1020, the second decoder 1040 decodes the color difference block to be decoded in a constant decoding mode. do. At this time, the constant decoding mode may be an inter mode or an intra mode.

In contrast, if it is checked that the motion information of the color difference block to be decoded is present in the motion information decoded by the third decoder 1020, the second decoder 1040 may appear in the mode information included in the decoded motion information. Analyze whether the decoding mode is inter mode or intra mode. In this case, the second decoder 1040 decodes the color difference block to be decoded according to the analyzed decoding mode.

According to the third embodiment of the present invention, the second decoder 1040 decodes the color difference block Cb or Cr according to the 'decoding mode of the luminance block having the same phase as that of the color difference block'. In this case, the image is preferably a 4: 2: 2 format or a 4: 4: 4 format.

According to the fourth embodiment of the present invention, the second decoder 1040 may decode the chrominance block Cb or Cr by decoding the plurality of luminance blocks including the luminance block having the same phase as that of the chrominance block. 'In consideration of'. For example, the second decoder 1040 may decode the chrominance block into a `` decoding mode of a luminance block having a phase equal to the phase of the chrominance block '' and `` a luminance block adjacent to a luminance block having a phase equal to the phase of the chrominance block. '' The decoding can be performed according to the decoding mode determined according to whether or not the modes' match. In this case, if the decoding mode of the luminance block having the same phase as the phase of the chrominance block and the decoding mode of the luminance block adjacent to the luminance block having the same phase as the phase of the chrominance block, the second decoding unit ( The 1040 may decode the chrominance block according to the decoding mode of the luminance block having the same phase as that of the chrominance block. In contrast, if the decoding mode of the luminance block having the same phase as the phase of the chrominance block and the decoding mode of the luminance block adjacent to the luminance block having the same phase as the phase of the chrominance block, the second decoding unit ( The 1040 may decode the color difference block according to a predetermined decoding mode (eg, an inter mode). In the case of the fourth embodiment of the present invention, the video is preferably in 4: 2: 2 format.

Meanwhile, all of the luminance blocks reconstructed by the first decoder 1030 and the color difference blocks reconstructed by the second decoder 1040 are output through the output terminal OUT 7. The output terminal OUT 7 is the same as the output terminal OUT 3 or OUT 4 shown in FIG. 3.

FIG. 11 is a block diagram of an embodiment 1040A for explaining the second decoder 1040 according to the first, third, or fourth embodiment of the present invention. 1110 and the chrominance component decoder 1120. Referring to FIG. 11, it is assumed that the color difference block to be decoded by the second decoder 1040 is decoded according to the inter mode.

The motion vector determiner 1110 determines the motion vector of the color difference block Cb or Cr input through the input terminal IN 7 in consideration of the motion vectors of one or more luminance blocks corresponding to the color difference block. For example, the motion vector determiner 1110 may determine a motion vector of the chrominance block as the motion vector of the luminance block adjacent to the luminance block having the same phase as the phase of the chrominance block and the luminance having the same phase as the phase of the chrominance block. It may be determined considering the motion vector of the block. When all eight blocks shown in FIG. 4B are decoded in inter mode, the motion vector determiner 1110 exemplarily illustrates an operation of the motion vector determiner 1110 using the bar illustrated in FIG. 4B. Motion vectors of each of the four (fourth block, fifth block, sixth block, and seventh block) may be calculated according to Equation 1 above.

The color difference component encoder 1120 decodes the color difference block input through the input terminal IN 7 in consideration of the determined motion vector, and outputs the decoded result through the output terminal OUT 8. The output terminal OUT 8 may be the same as the above-described output terminal OUT 7.

FIG. 12 is a diagram for explaining a principle of encoding / decoding an image using a 1MV scheme. The 1 MV (motion vector) scheme refers to a coding / decoding scheme in which a maximum of one motion vector is required for one macroblock. For convenience of description, the image shown in FIG. 12 is an image having a 4: 2: 0 format.

If the image is encoded / decoded using the 1MV method as described above, the encoding mode (or decoding mode) of the luminance blocks 1212, 1214, 1216, and 1218 (1232, 1234, 1236, and 1238) and the blue color difference block 1220 and 1240 are used. The coding modes (or decoding modes) of and the coding modes (or decoding modes) of the red color yarn blocks 1222 and 1242 are the same as shown in FIG. 12.

FIG. 13 is a flowchart of a first exemplary embodiment for explaining an image encoding method according to the present invention. After encoding a luminance block, encoding the color difference block according to an encoding mode determined in consideration of an encoding mode of the luminance block. (1313-1340 steps).

The first encoder 512 encodes the luminance block for each luminance block according to a preset encoding mode (Step 1310).

After operation 1310, the second encoder 514 encodes the color difference block into a plurality of encoding modes among preset encoding modes for each luminance block (steps 1320 to 1340).

In detail, the second encoder 514 determines whether at least half of the preset encoding modes for each luminance block are the inter modes (step 1320). In operation 1320, it may be determined whether "at least half of the preset encoding modes for each luminance block are inter modes", or, as shown in FIG. "Can be judged.

If it is determined in step 1320 that the inter mode, the second encoder 514 encodes the color difference block in the inter mode (step 1330). In contrast, if it is determined that the intra mode is detected in operation 1320, the second encoder 514 encodes the color difference block in the intra mode (operation 1340).

14 is a flowchart of a first exemplary embodiment for explaining an image decoding method according to the present invention. After decoding a luminance block, steps of decoding the chrominance block according to a decoding mode determined in consideration of the decoding mode of the luminance block. (Steps 1410-1432).

The third decoder 1020 decodes the motion information (step 1410), and the first decoder 1030 determines whether the block to be decoded is the luminance block (step 1412). In the figure, N denotes the decoding order, which may be t, u, or v described above.

If it is determined in operation 1412 that the block is a luminance block, the first decoder 1030 determines whether motion information of the block to be decoded is present in the motion information decoded in operation 1410 (operation 1414).

If it is determined in step 1414 that it does not exist, the first decoder 1030 decodes the block to be decoded in the inter mode (step 1416). However, in operation 1416, the block to be decoded may be decoded in the intra mode.

On the other hand, if it is determined in step 1414, the first decoder 1030 analyzes the motion information of the block to be decoded (step 1418).

After operation 1418, the first decoder 1030 determines whether the operation is analyzed as an intra mode in operation 1418 (operation 1420).

If it is determined in step 1418 that it is analyzed as an intra mode (step 1420), the first decoder 1030 decodes the block to be decoded in the intra mode (step 1422). In contrast, if it is determined in step 1418 that it is determined to be an inter mode (step 1420), it proceeds to step 1416.

If it is determined in step 1412 that the color difference block is determined, the second decoder 1040 determines whether at least half of the decoding modes of all the luminance blocks included in the same macroblock as the block to be decoded are the inter mode. Step 1424).

However, in operation 1424, as illustrated, more than half of decoding modes of all luminance blocks included in the same macroblock as the block to be decoded may be determined to be an inter mode.

If it is determined in step 1424 that it is not the inter mode, the second decoder 1040 decodes the block to be decoded in the intra mode (step 1426).

On the other hand, if it is determined in step 1424 that the inter mode, the second decoder 1040 decodes the block to be decoded in the inter mode (step 1428).

After operation 1416, operation 1426, or operation 1428, operation 1430 determines whether all blocks of the macroblock are decoded. If it is determined that there is an undecoded block in operation 1430, the process proceeds to operation 1412 through operation 1432 in order to decode a block having a decoding rank.

15 to 17 are diagrams of a first embodiment for explaining a principle of encoding / decoding an image using a 4MV scheme. The 4MV (motion vector) method refers to an encoding / decoding method when four motion vectors are required for one macroblock (strictly, luminance blocks in the macroblock).

The macroblock shown in FIG. 15 is a macroblock of an image having a 4: 2: 0 format.

15A, each of the luminance blocks 1512, 1514, 1516, and 1518 is encoded / decoded in an intra mode, an inter mode, an inter mode, and an inter mode. In this case, a plurality of coding modes (or decoding modes) among the coding modes (or decoding modes) of the luminance blocks 1512, 1514, 1516, and 1518 are in the inter mode. Therefore, the blue color difference block 1520 is encoded / decoded in the inter mode. Similarly, the red color difference block 1530 is also encoded / decoded in the inter mode.

Similarly, in FIG. 15B, each of the luminance blocks 1542, 1544, 1546, and 1548 is encoded / decoded in an intra mode, an intra mode, an intra mode, and an inter mode. In this case, a plurality of coding modes (or decoding modes) of the coding modes (or decoding modes) of the luminance blocks 1542, 1544, 1546 and 1548 are intra modes. Therefore, the blue color difference block 1550 is encoded / decoded in the intra mode. Similarly, the red color difference block 1560 is also encoded / decoded in the intra mode.

The macroblock shown in FIG. 16 is a macroblock of an image having a 4: 2: 2 format.

As shown in FIG. 16A, each of the luminance blocks 1612, 1614, 1616, and 1618 is encoded / decoded in an intra mode, an inter mode, an inter mode, and an inter mode. In this case, a plurality of encoding modes (or decoding modes) among the encoding modes (or decoding modes) of the luminance blocks 1612, 1614, 1616, and 1618 are inter modes. Therefore, each of the blue color difference blocks 1622 and 1624 are encoded / decoded in the inter mode. Similarly, each of the red color difference blocks 1632 and 1634 is also encoded / decoded in the inter mode.

Similarly, as shown in FIG. 16B, each of the luminance blocks 1641, 1644, 1646, and 1648 is encoded / decoded in an intra mode, an intra mode, an intra mode, and an inter mode. In this case, a plurality of encoding modes (or decoding modes) among the encoding modes (or decoding modes) of the luminance blocks 1644, 1644, 1646, and 1648 are intra modes. Therefore, each of the blue color difference blocks 1652 and 1654 is encoded / decoded in the intra mode. Similarly, each of the red color difference blocks 1662 and 1664 is also encoded / decoded in the intra mode.

The macroblock shown in FIG. 17 is a macroblock of an image having a 4: 4: 4 format.

As shown in FIG. 17A, each of the luminance blocks 1712, 1714, 1716, and 1718 is encoded / decoded in an intra mode, an inter mode, an inter mode, and an inter mode. In this case, a plurality of encoding modes (or decoding modes) among the encoding modes (or decoding modes) of the luminance blocks 1712, 1714, 1716, and 1718 are inter modes. Therefore, each of the blue color difference blocks 1722, 1724, 1726, and 1728 is encoded / decoded in the inter mode. Similarly, each of the red color difference blocks 1732, 1734, 1736, and 1738 is also encoded / decoded in the inter mode.

Similarly, as shown in FIG. 17B, each of the luminance blocks 1742, 1744, 1746, and 1748 is encoded / decoded into an intra mode, an intra mode, an intra mode, and an inter mode. In this case, a plurality of encoding modes (or decoding modes) among the encoding modes (or decoding modes) of the luminance blocks 1742, 1744, 1746, and 1748 are intra modes. Therefore, each of the blue color difference blocks 1552, 1754, 1756, 1758 is encoded / decoded in the intra mode. Similarly, each of the red color difference blocks 1762, 1764, 1766, and 1768 is also encoded / decoded in the intra mode.

18 is a flowchart of a second embodiment for explaining a video encoding method according to the present invention.

The first encoder 512 encodes the luminance block according to a preset encoding mode for each luminance block (step 1810), and the second encoder encodes the chrominance block according to a preset encoding mode for each color difference block (step 1820). ).

As shown, the step 1820 may be performed after the step 1810 or, as illustrated, may be performed before the step 1810 or may be performed simultaneously with the step 1810.

19 is a flowchart of a second embodiment for explaining an image decoding method according to the present invention, in which a luminance block is decoded in accordance with a decoding mode preset for each luminance block, and a chrominance block is decoded in accordance with a decoding mode preset for each color difference block. It consists of the steps (steps 1910-1924).

The third decoder 1020 decodes the motion information (step 1910).

After operation 1910, the first decoder 1030 or the second decoder 1040 determines whether motion information of the block to be decoded is present in the motion information decoded in operation 1910 (operation 1912).

If it is determined in step 1912 that the first decoder 1030 or the second decoder 1040 analyzes the motion information of the block to be decoded (step 1914).

After operation 1914, the first decoder 1030 or the second decoder 1040 determines whether it is analyzed as an intra mode in operation 1914 (operation 1916).

If it is determined in step 1914 that it is analyzed as an intra mode (step 1916), the first decoder 1030 or the second decoder 1040 decodes the block to be decoded in the intra mode (step 1918). In contrast, if it is determined in step 1914 that it is determined to be an inter mode (step 1916), the first decoder 1030 or the second decoder 1040 decodes the block to be decoded in the inter mode (1920). step).

On the other hand, if it is determined in step 1912 that it does not exist, it may proceed to step 1920 as shown, or unlike the block shown to be decoded in the intra mode can be decoded.

20 is a diagram for describing a principle of encoding / decoding an image using a 4MV scheme.

The macroblock illustrated in FIG. 20A is a macroblock of an image having a 4: 2: 0 format.

As shown in FIG. 20A, each of the luminance blocks 2012, 2014, 2016, and 2018 is encoded / decoded in an intra mode, an inter mode, an inter mode, and an inter mode. In addition, the blue color difference block 2020 is encoded / decoded in the inter mode, and the red color difference block 2030 is encoded / decoded in the intra mode. As described above, there may be no relation between the coding mode (or decoding mode) of the luminance block, the coding mode (or decoding mode) of the blue color difference block, and the encoding mode (or decoding mode) of the red color difference block.

The macroblock illustrated in FIG. 20B is a macroblock of an image having a 4: 2: 2 format.

As shown in FIG. 20B, each of the luminance blocks 2042, 2044, 2046, and 2048 is encoded / decoded in an intra mode, an intra mode, an intra mode, and an inter mode. In addition, each of the blue color difference blocks 2052 and 2054 is encoded / decoded in an inter mode and an intra mode, and each of the red color difference blocks 2062 and 2064 is encoded / decoded in an intra mode and an inter mode. As described above, there may be no relation between the coding mode (or decoding mode) of the luminance block, the coding mode (or decoding mode) of the blue color difference block, and the encoding mode (or decoding mode) of the red color difference block.

The macroblock shown in FIG. 20C is a macroblock of an image having a 4: 4: 4 format.

As shown in FIG. 20C, each of the luminance blocks 2072, 2074, 2076, and 2078 is encoded / decoded in an intra mode, an intra mode, an intra mode, and an inter mode. In addition, each of the blue color difference blocks 2082, 2084, 2086, and 2088 is encoded / decoded in an inter mode, an intra mode, an intra mode, and an inter mode, and each of the red color difference blocks 2092, 2094, 2096, and 2098 is interleaved. Coded / decoded in mode, inter mode, inter mode and inter mode. As described above, there may be no relation between the coding mode (or decoding mode) of the luminance block, the coding mode (or decoding mode) of the blue color difference block, and the encoding mode (or decoding mode) of the red color difference block.

21 is a flowchart of a third exemplary embodiment for explaining an image encoding method according to the present invention. After encoding a luminance block, encoding the color difference block according to an encoding mode determined in consideration of an encoding mode of the luminance block. (Steps 2110-2120).

The first encoder 512 encodes the luminance block for each luminance block according to a preset encoding mode (step 2110).

After operation 2110, the second encoder 514 encodes the color difference block according to the encoding mode of the luminance block having the same phase as the phase of the color difference block (step 2120).

FIG. 22 is a flowchart of a third exemplary embodiment for explaining an image decoding method according to the present invention. After decoding a luminance block, decoding the color difference block according to a decoding mode determined in consideration of a decoding mode of the luminance block. (Steps 2210-2232).

The third decoder 1020 decodes the motion information (step 2210), and the first decoder 1030 determines whether the block to be decoded is the luminance block (step 2212). In the figure, N denotes the decoding order, which may be t, u, or v described above.

If it is determined in operation 2212 that it is a luminance block, the first decoder 1030 determines whether motion information of the block to be decoded exists in the motion information decoded in operation 2210 (operation 2214).

If it is determined in step 2214, the first decoder 1030 analyzes the motion information of the block to be decoded (step 2216).

After operation 2216, the first decoder 1030 determines whether an intra mode is analyzed in operation 2216 (operation 2218).

If it is determined in step 2216 that the intra mode is analyzed (step 2218), the first decoder 1030 decodes the block to be decoded in the intra mode (step 2220). In contrast, if it is determined in step 2216 that it is determined to be an inter mode (step 2218), the first decoder 1030 decodes the block to be decoded in the inter mode (step 2222).

On the other hand, if it is determined in step 2214 that it does not exist, it may proceed to step 2222 as shown, or unlike the block shown to be decoded may be decoded in the intra mode.

If it is determined in step 2212 that it is a chrominance block, the second decoder 1040 determines whether the decoding mode of the luminance block having the same phase as the phase of the block to be decoded is an inter mode or an intra mode. (Step 2224).

If it is determined in step 2224 that the inter mode is determined, the second decoder 1040 decodes the block to be decoded in the inter mode (step 2226). On the other hand, if it is determined that the intra mode in operation 2224, the second decoder 1040 decodes the block to be decoded in the intra mode (operation 2228).

After step 2220, step 2222, step 2226, or step 2228, step 2230 determines whether all blocks of the macroblock have been decoded. If it is determined that there is an undecoded block in operation 2230, the process proceeds to operation 2212 through operation 2232 to decode a block having a decoding rank.

FIG. 23 is a diagram for describing a principle of encoding / decoding an image using a 4MV scheme.

The macroblock shown in (a) of FIG. 23 is a macroblock of an image having a 4: 2: 2 format.

As shown in (a) of FIG. 23, the phase of the luminance block 2312, 2314, 2316, or 2318 is the luminance blocks 2312, 2314, of the luminance block 2312, 2314, 2316, or 2318. 2316, and 2318). The phase of the blue color difference block 2322 or 2324 means a position within the color difference blocks 2232, 2324, 2332, and 2334 of the blue color difference block 2232 or 2324. Similarly, the phase of the red chrominance block 2332 or 2334 means the position within the chrominance blocks 2322, 2324, 2332, and 2334 of the red chrominance block 2332, or 2334.

As shown in (a) of FIG. 23, each of the luminance blocks 2312, 2314, 2316, and 2318 is encoded / decoded in an intra mode, an intra mode, an intra mode, and an inter mode.

Accordingly, the blue color difference block 2322 is encoded / decoded in the encoding mode (or decoding mode) of the luminance block 2312, and the blue color difference block 2324 is the encoding mode (or decoding mode) of the luminance block 2316. The red color difference block 2332 is encoded / decoded by the encoding mode (or decoding mode) of the luminance block 2314, and the red color difference block 2334 is encoded by the encoding mode (or , Decoding mode).

The macroblock shown in FIG. 23B is a macroblock of an image having a 4: 4: 4 format.

As shown in FIG. 23B, the phase of the luminance block 2342, 2344, 2346, or 2348 is the luminance blocks 2342, 2344, of the luminance block 2234, 2344, 2346, or 2348. 2346, and 2348). On the other hand, the phase of the blue color difference block 2352, 2354, 2356, or 2358 is within the blue color difference blocks 2352, 2354, 2356, and 2358 of the blue color difference block 2352, 2354, 2356, or 2358. Means the position of. Similarly, the phase of red color difference block 2322, 2364, 2366, or 2368 is within the red color difference blocks 2322, 2364, 2366, or 2368 of the red color difference block 2236, 2364, 2366, or 2368. Means the position of.

As shown in FIG. 23B, each of the luminance blocks 2342, 2344, 2346, and 2348 is encoded / decoded in an intra mode, an intra mode, an intra mode, and an inter mode.

Accordingly, the blue color difference block 2352 is encoded / decoded in the encoding mode (or decoding mode) of the luminance block 2342, and the blue color difference block 2354 is the encoding mode (or decoding mode) of the luminance block 2344. Are encoded / decoded with the blue color difference block 2356 encoded / decoded with the encoding mode (or decoding mode) of the luminance block 2346, and the blue color difference block 2358 is encoded with the encoding mode (or , Decoding mode).

Similarly, the red color difference block 2362 is encoded / decoded in the encoding mode (or decoding mode) of the luminance block 2342, and the red color difference block 2264 is the encoding mode (or decoding mode of the luminance block 2344). ) Is encoded / decoded into the encoding mode (or decoding mode) of the luminance block 2346, and the red chrominance block 2368 is encoded into the encoding mode of the luminance block 2348. Or in decoding mode).

FIG. 24 is a flowchart of a fourth exemplary embodiment for explaining an image encoding method according to the present invention. After encoding a luminance block, the color difference block is determined in consideration of encoding modes of one or more luminance blocks corresponding to the color difference block. And encoding according to an encoding mode (steps 2410 to 2440).

The first encoder 512 encodes the luminance block according to a preset encoding mode for each luminance block (step 2410).

After operation 2410, the second encoder 514 sets the chrominance block to 'encoding mode of the luminance block having the same phase as the phase of the chrominance block' and 'luminance adjacent to the luminance block having the same phase as the phase of the chrominance block'. It is determined whether the encoding modes of the blocks match (step 2420).

If it is determined in operation 2420, the second encoder 514 encodes the color difference block according to the encoding mode of the luminance block having the same phase as the phase of the color difference block (operation 2430).

In contrast, if it is determined that there is a mismatch in operation 2420, the second encoder 514 encodes the color difference block according to a predetermined encoding mode (eg, an inter mode) (operation 2440).

FIG. 25 is a flowchart of a fourth exemplary embodiment for explaining an image decoding method according to the present invention. After decoding a luminance block, the color difference block is determined in consideration of decoding modes of one or more luminance blocks corresponding to the color difference block. And decoding according to a decoding mode (steps 2510 to 2532).

The third decoder 1020 decodes the motion information (step 2510), and the first decoder 1030 determines whether the block to be decoded is the luminance block (step 2512). In the figure, N denotes the decoding order, which may be t, u, or v described above.

If it is determined in step 2512 that it is a luminance block, the first decoder 1030 determines whether motion information of the block to be decoded exists in the motion information decoded in step 2510 (step 2514).

If it is determined in step 2514, the first decoder 1030 analyzes the motion information of the block to be decoded (step 2516).

After operation 2516, the first decoder 1030 determines whether an intra mode is analyzed in operation 2516 (operation 2518).

If it is determined in step 2516 that it is analyzed as an intra mode (step 2518), the first decoder 1030 decodes the block to be decoded in an intra mode (step 2520). In contrast, if it is determined in step 2516 that it is determined to be an inter mode (step 2518), the first decoder 1030 decodes the block to be decoded in the inter mode (step 2522).

On the other hand, if it is determined in step 2514 that it does not exist, it may proceed to step 2522 as shown, or unlike the block shown to be decoded in the intra mode.

If it is determined in step 2512 that it is a chrominance block, the second decoding unit 1040 has a decoding mode of the luminance block having the same phase as that of the block to be decoded and has the same phase as that of the block to be decoded. It is determined whether or not the decoding mode of the luminance block adjacent to the luminance block matches the decoding mode (step 2524).

If it is determined in step 2524, the second decoder 1040 decodes the block to be decoded according to the 'decoding mode of the luminance block having the same phase as the phase of the block to be decoded' (step 2526). ). On the other hand, if it is determined that there is a mismatch in step 2524, the second decoder 1040 decodes the block to be decoded in a predetermined decoding mode (for example, an inter mode) (step 2528).

After step 2520, step 2252, step 2526, or step 2528, step 2530 determines whether all blocks of the macroblock have been decoded. If it is determined that there is an undecoded block in operation 2530, the process proceeds to operation 2512 through operation 2532 to decode a block having a decoding rank.

FIG. 26 is a diagram for explaining a principle of encoding / decoding an image using a 4MV scheme.

The macroblock shown in FIG. 26 is a macroblock of an image having a 4: 2: 2 format.

As shown in FIG. 26, the phase of the luminance block 2612, 2614, 2616, or 2618 is the luminance blocks 2612, 2614, 2616, and 2620, 2614, 2616, or 2618 of the luminance block 2612. 2618). The phase of the blue color difference block 2622 or 2624 means a position within the color difference blocks 2622, 2624, 2632, and 2634 of the blue color difference block 2622 or 2624. Similarly, the phase of the red color difference block 2632, or 2634 means the position within the color difference blocks 2622, 2624, 2632, and 2634 of the red color difference block 2632, or 2634.

As shown in FIG. 26, each of the luminance blocks 2612, 2614, 2616, and 2618 is encoded / decoded in an intra mode, an intra mode, an intra mode, and an inter mode.

"Encoding mode / decoding mode (i.e., intra mode) of luminance block 2612 having a phase equal to that of blue chrominance block 2622" and "luminance block having a phase equal to that of blue chrominance block 2622 Since the encoding mode / decoding mode (ie, the intra mode) of the luminance block 2614 adjacent to 2612 coincides, the encoding mode / decoding mode of the blue color difference block 2622 is the same as the phase of the blue color difference block 2622. Coding mode / decoding mode (ie, intra mode) of the luminance block 2612 having a phase. Accordingly, the blue color difference block 2622 is encoded / decoded according to the intra mode. Meanwhile, the luminance block adjacent to the luminance block 2612 is preferably a luminance block 2614 adjacent to the luminance block 2612 in the horizontal direction.

"Encoding mode / decoding mode (i.e., intra mode) of luminance block 2616 having the same phase as that of blue chrominance block 2624" and "luminance block having the same phase as the phase of blue chrominance block 2624 Since the encoding mode / decoding mode (i.e., inter mode) of the luminance block 2618 adjacent to 2616 " is inconsistent, the encoding mode / decoding mode of the blue color difference block 2624 is a constant encoding mode / constant decoding mode (e.g., For example, inter mode). Accordingly, the blue color difference block 2624 is encoded / decoded according to the inter mode. Meanwhile, the luminance block adjacent to the luminance block 2616 is preferably a luminance block 2618 adjacent to the luminance block 2616 in a horizontal direction.

"Encoding mode / decoding mode (i.e., intra mode) of luminance block 2614 having the same phase as that of red chrominance block 2632" and "luminance block having the same phase as the phase of red chrominance block 2632 Since the encoding mode / decoding mode (i.e., the intra mode) of the luminance block 2612 adjacent to 2614 matches, the encoding mode / decoding mode of the red color difference block 2632 is the same as the phase of the red color difference block 2632. Coding mode / decoding mode (ie, intra mode) of the luminance block 2614 having a phase. Accordingly, the red color difference block 2632 is encoded / decoded according to the intra mode. Meanwhile, the luminance block adjacent to the luminance block 2614 is preferably a luminance block 2612 adjacent to the luminance block 2614 in the horizontal direction.

"Encoding mode / decoding mode (i.e., inter mode) of luminance block 2618 having the same phase as that of red chrominance block 2634" and "luminance block having the same phase as the phase of red chrominance block 2634 ( Since the encoding mode / decoding mode (ie, the intra mode) of the luminance block 2616 adjacent to 2618 " is inconsistent, the encoding mode / decoding mode of the red color difference block 2634 is a constant encoding mode / constant decoding mode (e.g., , Inter mode). Accordingly, the red color difference block 2634 is encoded / decoded according to the inter mode. Meanwhile, the luminance block adjacent to the luminance block 2618 is preferably a luminance block 2616 adjacent to the luminance block 2618 in the horizontal direction.

The program for executing the image encoding and decoding method according to the present invention mentioned above on a computer may be stored in a computer-readable recording medium. Here, the computer-readable recording medium may be a magnetic storage medium (for example, a ROM, a floppy disk, a hard disk, etc.), and an optical reading medium (for example, a CD-ROM, a DVD). : Digital Versatile Disc).

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

As described above, the method and the apparatus for encoding and decoding an image according to the present invention allow the encoder for encoding an image in a 4MV scheme to encode the chrominance block according to an encoding mode determined in consideration of a predetermined encoding mode for each luminance block. Has an effect. Similarly, the image decoding method and apparatus according to the present invention have an effect that the decoder which decodes an image by the 4MV method decodes the chrominance block according to the encoding mode determined in consideration of the encoding mode preset for each luminance block.

According to another aspect of the present invention, there is provided an image encoding method and apparatus, wherein an encoder for encoding an image in 4 MV format encodes a luminance block in accordance with a preset encoding mode for each luminance block, And has an effect of encoding. Likewise, in the video decoding method and apparatus according to the present invention, a decoder for decoding an image by 4 MV method decodes the luminance block in accordance with a decoding mode preset for each luminance block, and the color difference block is decoded in accordance with a predetermined decoding mode And has the effect of decoding.

As described above, the method and the apparatus for encoding and decoding an image according to the present invention, when the image to be compressed (or reconstructed) is expressed separately by the luminance component and the chrominance component, selects an encoding mode (or decoding mode) of the chrominance component. It has the effect of providing a variety of ways to determine.

Furthermore, according to the method and apparatus for encoding and decoding an image according to the present invention, when a motion vector is considered during encoding (or decoding) of a luminance component and a chrominance component, the motion vector of the chrominance component image is a motion vector of the luminance component image. Can be determined using.

Accordingly, the image encoding and decoding method and apparatus according to the present invention provide various methods for determining a motion vector of a chrominance component image when a motion vector is considered during encoding (or decoding) of a luminance component and a chrominance component. Has an effect.

Claims (27)

Decoding the luminance block according to the luminance decoding mode of each luminance block; And Decoding a color difference block corresponding to the luminance block by using one of a plurality of color difference decoding modes associated with the luminance decoding mode of the luminance block, And the plurality of color difference decoding modes include a decoding mode identical to the luminance decoding mode of the luminance block. delete The image decoding method of claim 1, wherein the chrominance block encoding step decodes the chrominance block in consideration of decoding modes of the luminance block adjacent to the luminance block having the same phase and the luminance block having the same phase. Way. The method of claim 3, wherein the color difference block encoding step decodes the color difference block according to a decoding mode determined according to whether or not the decoding mode of the luminance block having the same phase matches the decoding mode of the adjacent luminance block. Image Decoding Method. The method of claim 4, wherein when the decoding mode of the adjacent luminance block and the decoding mode of the luminance block having the same phase coincide, the color difference block encoding step decodes the chrominance block according to the decoding mode of the adjacent luminance block. Image decoding method characterized in that. The method of claim 4, wherein when the decoding mode of the adjacent luminance block and the decoding mode of the luminance block having the same phase do not match, the chrominance block encoding step decodes the chrominance block according to a predetermined decoding mode. Image Decoding Method. The method of claim 6, wherein the constant decoding mode is an inter mode. A first decoder to decode a luminance block according to a decoding mode preset for each luminance block; And A second decoder configured to decode a color difference block corresponding to the luminance block by using one of a plurality of color difference decoding modes associated with the luminance decoding mode of the luminance block, And the plurality of color difference decoding modes include a decoding mode identical to the luminance decoding mode of the luminance block. delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete delete A computer-readable recording medium storing a program for executing the method of any one of claims 1 and 3 to 7 on a computer.

Images