Method and apparatus for encoding and decoding video signal according to directional intra-residual prediction

1. A method of encoding a video signal according to directional intra-residual prediction, comprising:

calculating first residual data by performing directional intra-prediction on a first block of a base layer with reference to a second block of the base layer;

calculating second residual data by performing directional intra-prediction on a third block of an enhancement layer that corresponds to the first block of the base layer with reference to a fourth block of the enhancement layer that corresponds to the second block of the base layer; and

encoding the third block according to the directional intra-residual prediction by obtaining third residual data that is a difference between the first residual data and the second residual data.

2. The method of claim 1 , wherein the encoding of the third block comprises encoding of the third residual data.

3. The method of claim 1 , wherein the first residual data is a difference value between the first block and the second block, and comprises directional information of the second block.

4. The method of claim 1 , wherein the second residual data is a difference value between the third block and the fourth block, and comprises directional information of the fourth block.

5. The method of claim 1 , wherein the third residual data comprises a difference between directional information included in the first residual data and directional information included in the second residual data.

6. The method of claim 1 , wherein the third residual data comprises information on a residual prediction mode that indicates the directional intra-residual prediction.

7. The method of claim 1 , wherein the third residual data comprises flag information that indicates whether to reuse directional information included in the first residual data.

8. The method of claim 1 , wherein the third residual data comprises flag information that indicates whether to adjust and use directional information included in the first residual data.

9. The method of claim 1 , wherein at least one of the second block and the fourth block exists in a third direction which is between a first direction and a second direction, which are adjacent to each other, for use in the directional intra-prediction.

10. The method of claim 9 , wherein the first and second directions are determined according to H.264 intraprediction standard.

11. A method of decoding a video signal according to directional intra-residual prediction, comprising:

extracting third residual data that is directional intra-residual prediction data on a third block of an enhancement layer from an enhancement-layer residual stream;

extracting first residual data that is a result of performing directional intra-prediction on a first block of a base layer corresponding to the third block from a base-layer residual stream;

calculating second residual data that is a result of performing directional intra-prediction on the third block by adding the third residual data and the first residual data; and

restoring the third block using the second residual data.

12. The method of claim 11 , wherein the first residual data is a difference value between the first block and a second block that the first block refers to according to the directional intra-prediction, and comprises directional information of the second block.

13. The method of claim 11 , wherein the second residual data is a difference value between the third block and a fourth block that the third block refers to according to the directional intra-prediction, and comprises directional information of the fourth block.

14. The method of claim 11 , wherein the third residual data comprises a difference between directional information included in the first residual data and directional information included in the second residual data.

15. The method of claim 11 , wherein the third residual data comprises information on a residual prediction mode that indicates the directional intra-residual prediction.

16. The method of claim 11 , wherein the third residual data comprises flag information that indicates whether to reuse directional information included in the first residual data.

17. The method of claim 11 , wherein the third residual data comprises flag information that indicates whether to adjust and use directional information included in the first residual data.

18. The method of claim 11 , wherein the first residual data and the second residual data are obtained with reference to a second block and a fourth block, respectively, and

wherein at least one of the second block and the fourth block exists in a third direction which is between a first direction and a second direction, which are adjacent to each other, for use in the directional intra-prediction.

19. The method of claim 18 , wherein the first and second directions are determined according to H.264 intraprediction standard.

20. A video encoder for encoding a video signal according to a directional intra-residual prediction, the video encoder comprising:

a base-layer intra-prediction unit which calculates first residual data by performing directional intra-prediction on a first block of a base layer with reference to a second block of the base layer;

an enhancement-layer intra-prediction unit which calculates second residual data by performing directional intra-prediction on a third block of an enhancement layer which corresponds to the first block of the base layer with reference to a fourth block of the enhancement layer which corresponds to the second block of the base layer; and

a residual encoding unit which encodes the third block according to the directional intra-residual prediction by obtaining third residual data that is a difference between the first residual data and the second residual data.

21. The video encoder of claim 20 , wherein, in encoding the third block, the residual encoding unit is configured to encode the third residual data.

22. The video encoder of claim 20 , wherein the first residual data is a difference value between the first block and the second block, and comprises directional information of the second block.

23. The video encoder of claim 20 , wherein the second residual data is a difference value between the third block and the fourth block, and comprises directional information of the fourth block.

24. The video encoder of claim 20 wherein the third residual data comprises a difference between directional information included in the first residual data and directional information included in the second residual data.

25. The video encoder of claim 20 , wherein the third residual data comprises information on a residual prediction mode that indicates the directional intra-residual prediction.

26. The video encoder of claim 20 , wherein the third residual data comprises flag information that indicates whether to reuse directional information included in the first residual data.

27. The video encoder of claim 20 , wherein the third residual data comprises flag information that indicates whether to adjust and use directional information included in the first residual data.

28. The video encoder of claim 20 , wherein at least one of the second block and the fourth block exists in a third direction that is between a first direction and a second direction, which are adjacent to each other, for use in the directional intra-prediction.

29. The video encoder of claim 28 , wherein the first and second directions are determined according to H.264 intraprediction standard.

30. A video decoder for decoding a video signal according to a directional intra-residual prediction, comprising:

a residual decoding unit which extracts third residual data that is directional intra-residual prediction data on a third block of an enhancement layer from an enhancement-layer residual stream;

a base-layer residual decoding unit which extracts first residual data that is a result of performing directional intra-prediction on a first block of a base layer corresponding to the third block from a base-layer residual stream;

an enhancement-layer residual decoding unit which calculates second residual data that is a result of performing directional intra-prediction on the third block by adding the third residual data and the first residual data; and

an enhancement-layer decoding unit which restores the third block using the second residual data.

31. The video decoder of claim 30 , wherein the first residual data is a difference value between the first block and a second block that the first block refers to according to the directional intra-prediction, and comprises directional information of the second block.

32. The video decoder of claim 30 , wherein the second residual data is a difference value between the third block and a fourth block that the third block refers to according to the directional intra-prediction, and comprises directional information of the fourth block.

33. The video decoder of claim 30 , wherein the third residual data comprises a difference between directional information included in the first residual data and directional information included in the second residual data.

34. The video decoder of claim 30 , wherein the third residual data comprises information on a residual prediction mode that indicates the directional intra-residual prediction.

35. The video decoder of claim 30 , wherein the third residual data comprises flag information that indicates whether to reuse directional information included in the first residual data.

36. The video decoder of claim 30 , wherein the third residual data comprises flag information that indicates whether to adjust and use directional information included in the first residual data.

37. The video decoder of claim 30 , wherein the first residual data and the second residual data are obtained with reference to the second block and the fourth block, respectively, and

wherein at least one of the second block and the fourth block exists in a third direction that is between a first direction and a second direction, which are adjacent to each other, for use in the directional intra-prediction.

38. The video decoder of claim 37 , wherein the first and second directions are determined according to H.264 intraprediction standard.