Method and apparatus for image encoding/decoding

1. A method of decoding an image, the method comprising:

generating a prediction block for a current block;

decoding information of a first block size to determine the first block size, wherein the first block size is determined by an encoder;

decoding information indicating whether a skip of a transform process is applied, in response to a comparison of the first block size with a current block size;

determining whether to perform an inverse transform on the current block based on the decoded information indicating whether the skip of the transform process is applied;

performing or skipping the inverse transform on the current block to generate a residual block for the current block;

reconstructing the current block based on the prediction block and the residual block; and

applying filtering on the reconstructed current block,

wherein the filtering comprises deblocking filtering.

2. The method of claim 1 , wherein in response to the decoded information indicating that the transform process is not performed, the inverse transform on the current block is skipped.

3. The method of claim 1 , wherein in response to the decoded information indicating that the transform process is performed, the inverse transform on the current block is performed.

4. The method of claim 1 , wherein in response to a value of transform_skip_flag being 1, the transform process is not performed and is skipped on the current block, and in response to the value of transform_skip_flag being 0, the transform process is performed on the current block.

5. The method of claim 4 , wherein the information indicating whether the skip of the transform process is applied comprises a flag indicating whether to perform the inverse transform on the current block based on the first block size.

6. The method of claim 1 , further comprising performing an inverse transform on the current block according to the current block size, in response to the current block size satisfying a condition in which the skip of the transform process is not applied.

7. The method of claim 6 , wherein the skip of the transform process is applied when the current block size is larger than 4×4 pixels.

8. A method of encoding an image, the method comprising:

generating a prediction block for a current block;

generating a residual block for the current block based on the prediction block;

encoding the residual block;

decoding the encoded residual block;

reconstructing the current block based on the prediction block and the decoded residual block; and

applying filtering on the reconstructed current block,

wherein the filtering comprises deblocking filtering, and

wherein the encoding of the residual block comprises

determining a first block size and encoding information of the first block size;

determining whether to apply a skip of a transform process on the current block based on a comparison of the first block size with a current block size; and

performing or skipping a transform on the current block to encode the residual block.

9. The method of claim 8 , further comprising encoding information indicating whether the skip of the transform process is applied to the current block.

10. The method of claim 9 , wherein in response to a determination that the skip of the transform process is applied to the current block, the information indicating whether the skip of the transform process is applied to the current block indicates that the transform on the current block is skipped.

11. The method of claim 10 , further comprising performing the transform on the current block according to the current block size, in response to the current block size satisfying a condition in which the skip of the transform process is not applied.

12. The method of claim 9 , wherein in response to a determination that the skip of the transform process is not applied to the current block, the information indicating whether the skip of the transform process is applied to the current block indicates that the transform on the current block is performed.

13. The method of claim 9 , wherein the information indicating whether the skip of the transform process is applied comprises a flag indicating whether to perform the transform on the current block based on the first block size.

14. The method of claim 13 , wherein the skip of the transform process is applied when the current block size is larger than 4×4 pixels.

15. The method of claim 8 , wherein in response to a value of transform_skip_flag being 1, the transform process is not performed and is skipped on the current block, and in response to the value of transform_skip_flag being 0, the transform process is performed on the current block.

16. A non-transitory computer readable recording medium storing a bitstream which is generated by an image encoding method, the method comprising:

generating a prediction block for a current block;

generating a residual block for the current block based on the prediction block;

encoding the residual block;

decoding the encoded residual block;

reconstructing the current block based on the prediction block and the decoded residual block; and

applying filtering on the reconstructed current block,

wherein the filtering comprises deblocking filtering, and

wherein the encoding of the residual block comprises

determining a first block size and encoding information of the first block size;

determining whether to apply the skip of the transform process on the current block based on a comparison of the first block size with a current block size; and

performing or skipping a transform on the current block to encode the residual block.