KR101918957B1 - Encoding method and apparatus for transformming hierarchical variable block and decoding method and apparatus - Google Patents

Abstract

A transcoding method and apparatus, and a decoding method and apparatus are provided. The transcoding method may convert the difference block according to the conversion type information determined in advance or adaptively. Then, any one of the transformed difference blocks can be determined as a final block.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a coding method and apparatus capable of performing hierarchical variable block conversion and a decoding method and apparatus using the same.

The present invention relates to a technique for dividing an input image into a plurality of blocks, dividing an encoded block among the divided blocks hierarchically and transcoding.

In general, when inter picture prediction coding is performed, the transcoding method applies transcoding by applying the same 4x4 or 8x8 transform block to the predictive divided block.

For example, the conventional transforming method can generate a differential block by performing motion prediction on 16 × 16, 16 × 8, 8 × 16, 8 × 8, 4 × 8, and 4 × 4 block modes . Then, the differential block can be transcoded using the 4x4 or 8x8 transform block. As described above, the conventional transcoding method can perform the same transcoding on the difference block regardless of the prediction mode, thereby reducing the coding efficiency.

Particularly, in the case of using the 8x8 transform block, there is a limitation that the conventional transformed encoding method can perform the transform encoding only when the prediction modes are 16x16, 16x8, 8x16, and 8x8 .

Accordingly, there is a need for a technique capable of improving coding efficiency by applying different transform coding according to the characteristics of an image.

The present invention provides a method and an apparatus, a decoding method, and an apparatus for generating conversion type information suitable for the size of an encoding block and transcoding the difference block based on the conversion type information.

A coding method according to an embodiment of the present invention includes the steps of generating a plurality of prediction blocks by predicting a coding block according to a plurality of prediction mode information, generating a plurality of prediction blocks by using the coding block and the plurality of prediction blocks, Transforming each of the differential blocks according to predefined transform type information or adaptively determined transform type information, and determining each of the transformed differential blocks as a final block .

In addition, in the step of determining as the final block, one of the transformed differential blocks having the best coding performance may be determined as a final block.

The method may further include calculating a rate-distortion cost of each of the converted differential blocks. The step of determining as the last block may then determine the last block based on the calculated rate-distortion cost.

The determining of the final block may include determining a differential block having the minimum rate-distortion cost as a final block, and determining whether to transmit the conversion type information and the prediction mode information applied to the final block Step < / RTI >

In addition, the step of determining whether or not to transmit the conversion type information and the prediction mode information applied to the last block may include: converting type information and prediction mode information applied to the last block; conversion type information of a neighboring block adjacent to the encoding block; And determine whether to transmit the conversion type information and the prediction mode information applied to the last block based on the information.

In addition, in the step of determining the final block, the additional information may be generated by combining the conversion type information and the prediction mode information applied to the final block and the coded block pattern (CBP) of the coding block.

The transforming each of the difference blocks may include adaptively determining a transform depth using at least one of a size of a unit block, a size of a coding block, and quantization information of a neighboring block, And determining the size of the transform block for each of the transform depths.

Generating a final prediction block by predicting the encoding block based on prediction mode information applied to the final block, generating a final difference block using the final prediction block and the encoding block, Transforming the final difference block based on the transform type information applied to the transform block, and quantizing and entropy-coding the transformed last difference block.

According to the present invention, the coding efficiency can be improved by transcoding the difference block based on the conversion type information corresponding to the size of the encoding block.

According to the present invention, the difference block can be fixedly transcoded according to the conversion type information defined in advance for the encoding block.

According to the present invention, the difference block can be adaptively transcoded according to the transform type information adaptively generated according to the encoding block.

1 is a flow chart for explaining a transcoding method according to an embodiment of the present invention.
2 is a flowchart illustrating a configuration for determining a final block in an encoding apparatus according to an embodiment of the present invention.
3 is a flowchart illustrating a configuration for encoding a final transformed differential block based on transform type information of a final block in an encoding apparatus according to an embodiment of the present invention.
4 is a diagram illustrating conversion type information applicable to an encoding block in an encoding apparatus according to an embodiment of the present invention.
5 is a diagram illustrating conversion type information when a conversion block having a size of a conversion block larger than a size of a prediction block is applied in an encoding apparatus according to an embodiment of the present invention.
6 is a block diagram illustrating a detailed configuration of an encoding apparatus according to an embodiment of the present invention.
7 is a flowchart illustrating a conversion decoding method according to an embodiment of the present invention.
8 is a block diagram showing a detailed configuration of a decoding apparatus according to a temporary example of the present invention.
FIG. 9 is a diagram for explaining a configuration using pattern information (CBP) of a coding block according to a temporary example of the present invention.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to or limited by the embodiments. In addition, the same reference numerals shown in the drawings denote the same members.

1 is a flow chart for explaining a transcoding method according to an embodiment of the present invention.

According to FIG. 1, in step 101, the encoding apparatus can divide an input image into a plurality of blocks. For example, the encoding apparatus can divide an input image into a plurality of unit blocks. Here, the unit block is a block having the maximum size among the encoding blocks, and may mean the most significant encoded block.

Then, in step 102, the encoding apparatus can determine the maximum conversion size and the division depth.

For example, the encoding apparatus can determine a maximum conversion size and a division depth of a coding block to be applied to a difference block generated by using a prediction block of a unit block and a unit block. At this time, the encoding apparatus can determine the maximum conversion size and the division depth based on the size of the unit block. Further, the encoding apparatus may determine the maximum transform size and the depth of division using the quantization information of the neighboring blocks.

Then, in step 103, the encoding device can divide the unit block into a plurality of encoding blocks. At this time, the encoding apparatus can divide the unit block into a plurality of encoding blocks based on the maximum conversion size and the division depth.

Next, in step 104, the encoding apparatus can generate a plurality of prediction blocks for the encoding block. At this time, the encoding apparatus can generate a plurality of prediction blocks by encoding the encoded blocks in accordance with the plurality of prediction modes.

For example, the encoding apparatus can generate a predictive block by predicting an encoded block using an inter-picture prediction mode or an intra-picture prediction mode. Here, the inter picture prediction mode may include prediction modes such as 32x32, 16x16, 16x8, 8x16, 8x8, 8x4, 4x8, and 4x4. The intra prediction mode may include various directional prediction modes such as a DC prediction mode, a vertical prediction mode, and a horizontal prediction mode.

First, in the case of using the inter picture prediction mode, the encoding apparatus includes a prediction block when a 16 × 16 prediction mode is applied, a prediction block when a 16 × 8 prediction mode is used, , And a prediction block in the case of using the 4x4 prediction mode can be generated. When the intra prediction mode is used, the encoding device can generate a prediction block in the case of using the DC prediction mode, a prediction block in the case of using the vertical prediction mode, and a prediction block in the case of using the horizontal prediction mode.

Then, in step 105, the encoding apparatus can generate the difference block using the prediction block and the encoding block. At this time, the encoding apparatus can generate the difference block through the difference between each prediction block and the encoding block.

For example, when five prediction modes are used to generate five prediction blocks, the coding apparatus generates a difference block 1 by subtracting the prediction block 1 from the encoding block, subtracts the prediction block 2 from the encoding block, 2, and ... The difference block 5 can be generated by subtracting the prediction block 5 from the encoding block.

Next, in step 106, the encoding apparatus can convert a plurality of differential blocks, respectively, according to predefined transform type information or adaptively determined transform type information. Here, the conversion type information may include the size of the conversion block and the conversion depth. At this time, the conversion type information may be defined in advance based on at least one of the size of the unit block, the size of the encoding block, and the quantization information of the neighboring blocks, or may be adaptively determined. Here, the neighboring block means a block located adjacent to the encoding block.

Further, the conversion type information may be predefined as a single conversion type, determined adaptively, or may be predefined as a plurality of conversion types or may be determined adaptively. At this time, the conversion type may have a tree structure or a hierarchical structure.

For example, when the conversion type information defined in advance as the single conversion type is used, the size of the conversion block corresponding to the 16 × 16 prediction mode can be predefined as 16 × 16 and the conversion depth is 1. Then, the encoding apparatus can convert the differential block using a 16x16 transform block.

As another example, when the conversion type information defined in advance for a plurality of conversion types is used, the size of the conversion block corresponding to the 16 × 16 prediction mode is 16 × 16, 16 × 8, 8 × 16, 8 × 8, 2 < / RTI > Then, the encoding apparatus can convert the differential block using the 16x16 conversion block, convert the differential block using the 16x8 conversion block, and convert the differential block using the 8x16 conversion block. In addition, when the coded block is 64x64, the size of the transform block may be 64x64, the transform depth may be 3 or the transform block size may be 32x32, the transform depth may be 2, and so on. If the encoding block is 32x32, the size of the transform block may be defined as 16x16, the transform depth may be 2 or the transform block size may be 8x8, the transform depth may be 1, and so on.

As another example, the encoding apparatus may adaptively determine a conversion depth based on at least one of a size of a unit block, a size of a coding block, and quantization information of a neighboring block. Then, the encoding apparatus can determine the size of the transform block for each transform depth based on the size of the encoding block. At this time, the encoding apparatus can adaptively determine the conversion depth and the size of the conversion block based on the pixel value change or the motion information in the encoding block. For example, the encoding apparatus can determine the block size as a size of the transform block as the change in the pixel value in the encoding block is large or as the motion is large. Then, the encoding apparatus can determine the larger block size as the size of the transform block as the change in the pixel value in the encoding block is small or the motion is less. As described above, the encoding apparatus can adaptively determine the size of the transform block according to the characteristics of the image. Then, the determined block may be used to transform the difference block.

In step 107, the encoding apparatus can determine any one of the plurality of difference blocks as a final block. At this time, the encoding apparatus can determine any one of the plurality of differential blocks as the final block based on the coding performance of the differential block.

For example, the encoding apparatus can determine the last block using at least one of the rate-distortion cost of the difference block, the difference value of the difference block, and the transform coefficient value of the difference block.

Next, in step 108, the encoding apparatus can determine whether to transmit the prediction mode information and the conversion type information applied to the last block.

At this time, the encoding apparatus can determine whether to transfer the conversion type information of the last block to the decoding apparatus, based on the conversion type information of the neighboring blocks and the conversion type information of the last block. Likewise, the encoding apparatus can determine whether to transmit the prediction mode information of the last block to the decoding apparatus, based on the prediction mode information of the neighboring block and the prediction mode information of the last block. Here, the final block is a coded block.

For example, the encoding device can compare the conversion type information of the encoding block and the conversion type information of the neighboring block to determine whether or not they match. At this time, if they match, the encoding apparatus may not transmit the conversion type information of the encoding block to the decoding apparatus. Likewise, the encoding apparatus can compare the prediction mode information of the encoded block with the prediction mode information of the neighboring block to judge whether or not they match. At this time, if they match, the encoding apparatus may not transmit the prediction mode information of the encoding block to the decoding apparatus. Then, the decoding apparatus can restore the encoded block using the conversion type information and the prediction mode information of the neighboring blocks.

At this time, when the conversion type information and the prediction mode information of the encoding block do not match the conversion type information and the prediction mode information of the neighboring block, the encoding apparatus can transmit the conversion type information and the prediction mode information of the encoding block to the decoding apparatus .

Then, in step 109, the encoding apparatus can generate and transmit side information.

For example, when the conversion type information and the prediction mode information of the encoding block do not match the conversion type information and the prediction mode information of the neighboring block, the encoding device generates the coded block pattern (CBP) The additional information can be generated by combining the conversion type information and the prediction mode information applied to the prediction mode information. Then, the encoding apparatus can transmit the generated additional information to the decoding apparatus.

As described above, the encoding apparatus can reduce the amount of the additional information by combining the CBP information, the conversion type information, and the prediction mode information. At this time, when a single conversion type is used, the encoding apparatus may not transmit the additional information indicating the number or type to the decoding apparatus. For example, when the size of the transform block is N x N and the transform depth is 1, only the single transform type is used. Therefore, the encoding device decodes the additional information including the transform type information of the encoding block and the prediction mode information of the encoding block It does not have to be transmitted to the device.

2 is a flowchart illustrating a configuration for determining a final block in an encoding apparatus according to an embodiment of the present invention.

2, in step 201, the encoding apparatus can determine the encoding performance of each of the differential blocks. At this time, the encoding apparatus can use a rate-distortion cost, a difference value, a transform coefficient value or the like to determine the encoding performance.

In step 202, the encoding apparatus can determine any one of the plurality of differential blocks converted based on the determined encoding performance as a final block.

In one example, when the rate-distortion cost is used, the encoding apparatus can calculate the rate-distortion cost of each of the plurality of transformed difference blocks. Then, the encoding apparatus can determine a differential block having the minimum rate-distortion cost as a final block.

For example, if there are three converted difference blocks, the encoder calculates the rate-distortion cost 1 of the transformed difference block 1, calculates the rate-distortion cost 2 of the transformed difference block 2, 3 rate-distortion cost 3 can be calculated. Then, the encoding apparatus can select a rate-distortion cost that is the smallest among the rate-distortion costs 1 to 3. Then, the encoding apparatus can determine the converted difference block corresponding to the selected rate-distortion cost as a final block.

As another example, when the difference value is used, the encoding device can calculate the difference value of each of the plurality of converted difference blocks. Then, the encoding apparatus can determine the last block based on the calculated difference value.

As another example, when the transform coefficient value is used, the encoding device can calculate the transform coefficient value of each of the plurality of transformed difference blocks. Then, the encoding apparatus can determine the last block based on the calculated transform coefficient value.

3 is a flowchart illustrating a configuration for encoding a final transformed differential block based on transform type information of a final block in an encoding apparatus according to an embodiment of the present invention.

3, in step 301, the encoding device can generate a prediction block based on the prediction mode information applied to the last block.

Next, in step 302, the encoding apparatus can generate a final difference block using the generated prediction block and the encoding block.

Then, in step 303, the encoding apparatus can convert the final difference block based on the conversion type information applied to the last block.

Then, in step 304, the encoding apparatus quantizes the transformed last difference block, and entropy-codes the quantized final difference block. Then, the encoding apparatus can transmit the bitstream generated through the entropy encoding to the decryption apparatus.

3, a final prediction block is generated based on the prediction mode information applied to the last block, a final difference block is converted based on the conversion type information applied to the last block, and a configuration for quantizing and entropy-encoding the converted final difference block However, the present embodiment corresponds to the embodiment, and the encoding apparatus may directly generate the final prediction block and omit the structure for converting the final difference block, and may directly quantize and entropy-encode the final block. In other words, when the rate-distortion cost is used for coding performance determination, in the process of comparing the rate-distortion cost of the converted difference blocks, the encoding device determines the difference block having the minimum rate-distortion cost as the final block , Quantize the determined last block, and entropy-encode the last quantized block.

4 is a diagram illustrating conversion type information applicable to an encoding block in an encoding apparatus according to an embodiment of the present invention. 4, the size of the unit block is 8N x 8N, and the division depth is 3.

4, when the division depth is 3, the unit block 410 is divided into 4N × 4N coded blocks, 4N × 4N coded blocks are divided into 2N × 2N coded blocks, and 2N × 2N coded blocks are divided into And may be divided into NxN encoded blocks.

First, if the maximum transform size is 4N × 4N and the transform depth is 3, the transform type applicable to the 4N × 4N coding block 430 may be equal to 431. At this time, if the maximum transform size is 2N x 2N and the transform depth is defined as 2 for the 4N x 4N coding block 430, the transform type applicable to the 4N x 4N coding block 430 may be equal to 432. [

If the maximum transform size is 2N x 2N and the transform depth is 2 previously defined for the 2N x 2N coding block 440, the transform type applicable to the 2N x 2N coding block 440 may be equal to 441. [

If the maximum transform size is N × N and the transform depth is previously defined as 1 for the N × N encoding block 450, the transform type applicable to the N × N encoding block 450 may be equal to 451. In other words, the size of the transform block applicable to the NxN encoding block 450 may be four.

5 is a diagram illustrating conversion type information when a conversion block having a size of a conversion block larger than a size of a prediction block is applied in an encoding apparatus according to an embodiment of the present invention.

Referring to FIG. 5, the 4Nx4N coding block 510 may be divided into three 2Nx2N blocks and four NxN blocks. In this case, if the maximum transform size is 4N × 4N and the transform depth is 3, the transform type applicable to the 4N × 4N coding block 510 may be equal to 520.

6 is a block diagram illustrating a detailed configuration of an encoding apparatus according to an embodiment of the present invention.

6, the encoding apparatus 600 includes a predictive block generator 610, a differential block generator 620, a transformer 630, a final block determiner 640, a quantizer 650, and entropy encoding 660 < / RTI >

First, the prediction block generator 610 may generate a plurality of prediction blocks by predicting a coding block according to a plurality of prediction mode information.

Here, the prediction mode information may include an inter picture prediction mode and an intra prediction mode. The inter picture prediction mode may include prediction modes such as 16x16, 16x8, 8x16, 8x8, 8x4, 4x8, and 4x4. The intra prediction mode may include a DC prediction mode, a vertical prediction mode, a horizontal prediction mode, and the like.

The difference block generator 620 may generate a plurality of difference blocks using the encoding block and the plurality of prediction blocks. For example, the difference block generation unit 620 may generate a plurality of difference blocks by subtracting each of the encoding block and the plurality of prediction blocks.

The conversion unit 630 may convert the difference blocks according to the pre-defined conversion type information or adaptively determined conversion type information. At this time, the transform unit 630 may transform the difference blocks according to the transform type information that is defined or determined using at least one of the size of the unit block, the size of the encoding block, and the quantization information of the neighboring blocks.

Here, the conversion type information may include the size of the conversion block and the conversion depth. The conversion type information may be predefined or determined as a single conversion type or a plurality of conversion types. At this time, when a plurality of conversion types are used, the conversion type information may have a tree structure or a hierarchical structure.

For example, the transform unit 630 can determine the transform depth using at least one of the size of the unit block, the size of the encoding block, and the quantization information of the neighboring blocks. The transform unit 630 can determine the size of the transform block for each transform depth based on the size of the encoding block. Then, the transform unit 630 may transform the encoded block using the determined transform block size.

The final block determiner 640 can determine the coding performance of each of the transformed difference blocks. For example, the final block determiner 640 may determine a coding performance using a rate-distortion cost, a difference value, a transform coefficient value, and the like. Then, the final block determining unit 640 can determine the differential block having the best coding performance as the final block.

For example, when using the rate-distortion cost, the final block determination unit 640 can calculate the rate-distortion cost of each of the converted difference blocks. At this time, the final block determiner 640 can determine that coding performance is better as the rate-distortion cost is smaller. Then, the final block determiner 640 can determine a differential block having the minimum rate-distortion cost as a final block.

Then, when the last block is determined, the prediction block generator 610 can predict the coding block according to the prediction mode information applied to the last block to generate the final prediction block. The difference block generation unit 620 may generate the final difference block by subtracting the generated prediction block from the encoded block. Then, the converting unit 630 can convert the final difference block according to the conversion type information applied to the final block.

The quantization unit 650 may then quantize the transformed last differential block. The entropy encoding unit 650 can entropy-encode the quantized final difference block to output a bitstream.

Meanwhile, the final block determiner 640 can determine whether to transmit the prediction mode information of the encoding block and the conversion type information of the encoding block to the decoding device.

For example, the final block determining unit 640 can compare whether the conversion type information and the prediction mode information of the encoding block, the conversion type information of the neighboring block, and the prediction mode information coincide with each other. If they match, the final block determination unit 640 may not transmit the conversion type information and the prediction mode information of the encoding block to the decoding apparatus. If they do not match, the final block determination unit 640 can transmit the conversion type information and the prediction mode information of the encoding block to the decoding apparatus. At this time, in order to reduce the bit amount of the additional information transmitted to the decoding apparatus, the encoding apparatus can generate additional information by combining the conversion type information and the prediction mode information of the encoding block and the pattern information (CBP) of the encoding block . Then, the encoding apparatus can transmit the generated additional information to the decoding apparatus.

As described above, the transformation type is not fixed according to the size of the prediction block, but can be flexibly adapted to the transformation of the image by hierarchically varying the block of the difference block. For example, referring to FIG. 10, a variable block transform 1020 can be performed by applying 4 × 4 and 8 × 8 transform types in a 16 × 16 encoded block, applying an 8 × 16 transform type, etc. Do. In other words, the conversion type is fixed to only 4 × 4 and 8 × 8 in the 16 × 16 encoded block, and variable block conversion can be performed in various sizes according to the characteristics of the image without performing the division conversion (1010).

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

Referring to FIG. 7, first, in step 701, the decoding apparatus can receive a bitstream from a coding apparatus.

In step 702, the decoding apparatus can obtain the conversion type information and the prediction mode information of the encoding block. Here, the conversion type information of the encoding block is the conversion type information applied to the last block, and the prediction mode information of the encoding block may be the prediction mode information applied to the last block. And a conversion depth.

For example, the decoding apparatus can receive additional information from the encoding apparatus. Here, the additional information may be a combination of conversion type information of the encoding block, prediction mode information of the encoding block, and pattern information of the encoding block. Then, the decoding apparatus can obtain the conversion type information of the encoding block and the prediction mode information of the encoding block from the additional information.

As another example, when the conversion type information and the prediction mode information of the encoding block are identical with the conversion type information and the prediction mode information of the neighboring block, and the conversion type information and the prediction mode information of the encoding block are not received from the encoding device, Can obtain the conversion type information and the prediction mode information of the neighboring blocks.

Next, in step 703, the decoding apparatus can restore the difference block using the obtained conversion type information and prediction mode information. At this time, the decoding apparatus can restore the difference block using the conversion type information and prediction mode information of the last block. Also, the decoding apparatus may recover the difference block using the conversion type information and the prediction mode information of the neighboring blocks.

For example, the decoding apparatus can dequantize entropy-decoded blocks. Then, the decoding apparatus can restore the difference block by inversely transforming the dequantized block according to the obtained conversion type information.

In step 704, the decoding apparatus may generate a prediction block of the entropy-decoded block using the obtained prediction mode information.

In step 705, the decoding apparatus may restore the encoded block by adding the prediction block of the decoded block and the differential block generated through the inverse transform.

8 is a block diagram showing a detailed configuration of a decoding apparatus according to a temporary example of the present invention.

8, the decoding apparatus includes an entropy decoding unit 810, an information obtaining unit 820, an inverse quantization and inverse transforming unit 830, a prediction block generating unit 840, and a restoring unit 850 .

The entropy decoding unit 810 can entropy decode the bitstream received from the encoding apparatus.

Then, the information obtaining unit 820 can obtain the conversion type information of the last block and the prediction mode information of the last block from the entropy-decoded block. Here, the conversion type information may include the size of the conversion block and the conversion depth.

The inverse quantization and inverse transform unit 830 can dequantize the entropy-decoded blocks. The inverse quantization and inverse transform unit 830 can invert the inversely quantized block according to the transform type information of the last block to restore the difference block.

The prediction block generator 840 may generate a prediction block of the entropy-decoded block based on the prediction mode information of the final block.

Then, the restoring unit 850 can restore the encoded block by adding the generated prediction block and the restored difference block.

Meanwhile, the information obtaining unit 820 may adaptively determine the conversion type information based on at least one of the size of the unit block, the size of the encoding block, and the quantization information of the neighboring blocks. At this time, the conversion type information may be defined in advance based on at least one of the size of the unit block, the size of the encoding block, and the quantization information of the neighboring blocks. Then, the information obtaining unit 820 can obtain the conversion type information of the last block and the prediction mode information of the last block based on the conversion type information that is predefined or adaptively determined.

In this case, when the coding apparatus transmits the additional information generated by combining the conversion type information and the prediction mode information of the last block and the pattern information (CBP) of the coding block, the information obtaining unit 820 obtains, from the additional information, The pattern information CBP may be separated to obtain the conversion type information and the prediction mode information of the last block. For example, the information obtaining unit 820 can obtain the conversion type information and the prediction mode information of the last block by extracting the pattern information of the encoding block as shown in Table 1 below.

for (j = 0; j <4; j ++)
{
if (cbp & (1 << j))
{
T8_flag [j] = T8_flag;
} else {
T8_flag [j] = 0;
}
}

In Table 1, j indicates the number of the conversion block (0: upper left in Fig. 9, 3: lower right block in Fig. 9), T8_flag indicates conversion type information included in the additional information transmitted from the encoder, T8_flag [ Is the conversion type information corresponding to each 8x8 block using the block pattern information CBP.

According to Table 1, the transmitted 2-bit additional information can be restored to a total of 4 bits for each transform block using the pattern information of the encoding block.

While the invention has been shown and described with reference to certain preferred embodiments thereof, it will be understood by those of ordinary skill 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. This is possible.

Therefore, the scope of the present invention should not be limited to the described embodiments, but should be determined by the equivalents of the claims, as well as the claims.

610:
620: Difference block generation unit
630:
640:
650: Quantization unit
660: Entropy coding unit

Claims (11)

A prediction block generator for generating prediction blocks by performing prediction on the encoded blocks;
A difference block generation unit for generating a difference block for the encoding block based on the encoding block and the prediction block; And
And an encoding unit for encoding the difference block,
Wherein the encoding unit comprises:
Wherein the step of determining whether or not to perform the conversion on the differential block performs the conversion on the basis of the conversion type information for performing the conversion when it is determined to perform the conversion on the differential block, Gt;
Wherein the conversion type information includes a size of a conversion block,
The size of the transform block is determined based on the size of the encoding block,
Wherein the encoding block has a quadtree structure. The method according to claim 1,
Wherein the encoding unit comprises:
If it is determined not to perform the transform on the differential block,
And skips the transform for the difference block and quantizes the difference block. The method according to claim 1,
Wherein the conversion type information is determined based on a size of the encoding block. The method according to claim 1,
Wherein the transform type information is determined based on a hierarchical tree structure. The method according to claim 1,
Wherein the conversion type information is determined based on a maximum conversion size or conversion depth. A decoding unit which obtains an encoded difference block for a coded block from a bitstream and decodes the coded difference block;
A prediction block generator for generating prediction blocks by performing prediction on the encoded blocks; And
And a reconstruction unit for reconstructing the coded block based on the decoded difference block and the generated prediction block,
Wherein the decoding unit comprises:
Performs inverse transform on the differential block, decides whether or not to perform inverse transform on the differential block, and performs inverse transform based on the transform type information when it is determined to perform inverse transform on the differential block ,
Wherein the conversion type information includes a size of a conversion block,
The size of the transform block is determined based on the size of the encoding block,
Wherein the encoding block has a quadtree structure. The method according to claim 6,
Wherein the decoding unit comprises:
If it is determined that the inverse transform is not performed on the differential block,
Quantizing the differential block, and skipping the inverse transformation on the inversely quantized differential block. The method according to claim 6,
Wherein the conversion type information is determined based on the size of the encoding block. The method according to claim 6,
Wherein the conversion type information is determined based on a hierarchical tree structure. The method according to claim 6,
Wherein the conversion type information is determined based on a maximum conversion size or a conversion depth. A computer-readable recording medium storing a bit stream generated by a video encoding apparatus,
A prediction block generator for generating prediction blocks by performing prediction on the encoded blocks;
A difference block generation unit for generating a difference block for the encoding block based on the encoding block and the prediction block; And
And an encoding unit for encoding the difference block,
Wherein the encoding unit comprises:
Wherein the step of determining whether or not to perform the conversion on the differential block performs the conversion on the basis of the conversion type information for performing the conversion when it is determined to perform the conversion on the differential block, Gt;
Wherein the conversion type information includes a size of a conversion block,
The size of the transform block is determined based on the size of the encoding block,
Wherein the encoding block has a quadtree structure.

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