Methods and apparatus for spatially varying residue coding

• US 9,736,500 B2
• Filed: 07/01/2010
• Issued: 08/15/2017
• Est. Priority Date: 07/06/2009
• Status: Active Grant

• Current Assignee: Interdigital Vc Holdings, Inc. (InterDigital, Inc.)
• Original Assignee: Thomson Licensing (Vantiva SA)
• Inventors: Sole, Joel, Xu, Qian, Lu, Xiaoan, Zheng, Yunfei, Yin, Peng
• Primary Examiner(s): Patel, Jay
• Assistant Examiner(s): Habib, Irfan
• Application Number:
  US13/382,394
• Publication Number:
  US 20120099642A1
• Time in Patent Office: 2,602 Days
• Field of Search: 37524003
• CPC Class Codes: H04N 19/12 Selection from among a plurality of transforms or standards, e.g. selection between discrete cosine transform [DCT] and sub-band transform or selection between H.263 and H.264
• CPC Class Codes: H04N 19/122 Selection of transform size, e.g. 8x8 or 2x4x8 DCT; Selection of sub-band transforms of varying structure or type
• CPC Class Codes: H04N 19/176 the region being a block, e.g. a macroblock
• CPC Class Codes: H04N 19/33 in the spatial domain
• CPC Class Codes: H04N 19/46 Embedding additional information in the video signal during the compression process H04N19/517, H04N19/68, H04N19/70 take precedence
• CPC Class Codes: H04N 19/61 in combination with predictive coding
• CPC Class Codes: H04N 19/86 involving reduction of coding artifacts, e.g. of blockiness

Abstract

Methods and apparatus are provided for spatially varying residue coding. An apparatus includes a video encoder (300) for encoding picture data for at least a block in a picture by selecting a spatially varying encoding method for a residue corresponding to a difference between an original version of the block and at least one reference block. One or more transforms are used to transform a portion of the block and a remaining area of the block is encoded using an alternate encoding method with respect to the one or more transforms or is not encoded.

Claims

1. In a video decoder, a method, comprising:

decoding residue of a block of a picture in a video sequence from a bitstream;

wherein said decoding includes;

selecting a first decoding method to decode a first residue of a first sub-block of the block using a first inverse transform and selecting at least an alternate decoding method to decode a second residue of at least a second sub-block of the block using a second inverse transform, and

applying said first inverse transform on said first residue of said first sub-block and applying said second inverse transform on said second residue of said at least a second sub-block to obtain decoded residues for said first sub-block and for said second sub-block,

wherein the first inverse transform is different than the second inverse transform, and

wherein a position of an inverse transform is based on at least one of prediction data, a prediction mode, residue, and a motion vector of a previous block.

2. The method of claim 1, further comprising filtering at least a portion of residue using at least a filter to reduce or eliminate encoding artifacts therein.

3. The method of claim 2, wherein the at least a filter is configured as a pre-processing filter.

4. The method of claim 1, wherein the block is a prediction unit.

5. The method of claim 1, wherein the number of inverse transforms used for the block is based on at least one of said prediction data, said prediction mode, said residue, and said motion vector of said previous block.

6. An apparatus comprising:

a video decoder configured to decode a residue of a block of a picture in a video sequence from a bitstream;

wherein the video decoder is configured to;

select a first decoding method to decode a first residue of a first sub-block of the block using a first inverse transform and at least an alternate decoding method to decode a second residue of at least a second sub-block of the block using a second inverse transform, and

apply said first inverse transform on said first residue of said first sub-block and applying said second inverse transform on said second residue of said at least a second sub-block to obtain decoded residues for said first sub-block and for said second sub-block,

wherein the first inverse transform is different than the second inverse transform, and

wherein a position of an inverse transform is based on at least one of prediction data, a prediction mode, residue, and a motion vector of a previous block.

7. The apparatus of claim 6, wherein the video decoder comprises at least a memory and one or more processors.

8. The apparatus of claim 6, further comprising at least a filter configured to filter at least a portion of residue to reduce or eliminate encoding artifacts therein.

9. The apparatus of claim 8, wherein the at least a filter is configured as a pre-processing filter.

10. The apparatus of claim 6, wherein the block is a prediction unit.

11. The apparatus of claim 6, wherein the number of inverse transforms used for the block is based on at least one of said prediction data, said prediction mode, said residue, and said motion vector of said previous block.

12. In a video encoder, a method, comprising:

encoding residue of a block of a picture in a video sequence into a bitstream;

wherein said encoding includes;

selecting a first encoding method to encode a first residue of a first sub-block of the block using a first transform and selecting at least an alternate encoding method to encode a second residue of at least a second sub-block of the block using a second transform, and

applying said first transform on said first residue of said first sub-block and applying said second transform on said second residue of said at least a second sub-block to obtain encoded residues for said first sub-block and for said second sub-block,

wherein the first inverse transform is different than the second inverse transform, and

wherein a position of an inverse transform is based on at least one of prediction data, a prediction mode, residue, and a motion vector of a previous block.

13. The method of claim 12, further comprising filtering at least a portion of residue using at least a filter to reduce or eliminate encoding artifacts therein.

14. The method of claim 13, wherein the at least a filter is configured as a pre-processing filter.

15. The method of claim 12, wherein the block is a prediction unit.

16. The method of claim 12, wherein the number of inverse transforms used for the block is based on at least one of said prediction data, said prediction mode, said residue, and said motion vector of said previous block.

17. An apparatus comprising:

a video encoder configured to encode a residue of a block of a picture in a video sequence into a bitstream;

wherein the encoder is configured to;

select a first encoding method to encode a first residue of a first sub-block of the block using a first transform and at least an alternate encoding method to encode a second residue of at least a second sub-block of the block using a second transform, and

apply said first transform on said first residue of said first sub-block and applying said second transform on said second residue of said at least a second sub-block to obtain encoded residues for said first sub-block and for said second sub-block,

wherein the first inverse transform is different than the second inverse transform, and

wherein a position of an inverse transform is based on at least one of prediction data, a prediction mode, residue, and a motion vector of a previous block.

18. The apparatus of claim 17, wherein the video encoder comprises at least a memory and one or more processors.

19. The apparatus of claim 17, further comprising at least a filter configured to filter at least a portion of residue to reduce or eliminate encoding artifacts therein.

20. The apparatus of claim 19, wherein the at least a filter is configured as a pre-processing filter.

21. The apparatus of claim 17, wherein the block is a prediction unit.

22. The apparatus of claim 17, wherein the number of inverse transforms used for the block is based on at least one of said prediction data, said prediction mode, said residue, and said motion vector of said previous block.

23. A non-transitory processor readable medium having stored thereon an encoded bitstream, the encoded bitstream comprising:

an encoded residue of a block of a picture;

wherein a first spatially varying encoding method is selected to encode a first residue of a first sub-block of the block using a first transform, and at least an alternate encoding method is selected to encode a second residue of at least a second sub-block of the block using a second transform, apply said first transform on said first residue of said first sub-block and applying said second transform on said second residue of said at least a second sub-block to obtain encoded residues for said first sub-block and for said second sub-block,

wherein the first inverse transform is different than the second inverse transform, and

wherein a position of an inverse transform is based on at least one of prediction data, a prediction mode, residue, and a motion vector of a previous block.

24. The medium of claim 23, wherein at least a portion of residue is filtered using at least a filter to reduce or eliminate encoding artifacts therein.

25. The medium of claim 24, wherein the at least a filter is configured as a pre-processing filter.

26. The medium of claim 23, wherein the block is a prediction unit.

27. The medium of claim 23, wherein the number of inverse transforms used for the block is based on at least one of said prediction data, said prediction mode, said residue, and said motion vector of said previous block.

28. An apparatus comprising:

a transmitter configured to transmit a bitstream comprising an encoded residue of a block of a picture;

wherein encoding includes selecting a first encoding method to encode a first residue of a first sub-block of the block using a first transform and selecting at least an alternate encoding method to encode a second residue of at least a second sub-block of the block using a second transform, apply said first transform on said first residue of said first sub-block and applying said second transform on said second residue of said at least a second sub-block to obtain encoded residues for said first sub-block and for said second sub-block,

wherein the first inverse transform is different than the second inverse transform, and

wherein a position of an inverse transform is based on at least one of prediction data, a prediction mode, residue, and a motion vector of a previous block.

29. The apparatus of claim 28, further comprising at least a filter configured to filter at least a portion of residue to reduce or eliminate encoding artifacts therein.

30. The apparatus of claim 29, wherein the at least a filter is configured as a pre-processing filter.

31. The apparatus of claim 28, wherein the block is a prediction unit.

32. The apparatus of claim 28, wherein the number of inverse transforms used for the block is based on at least one of said prediction data, said prediction mode, residue, and said motion vector of said previous block.