SIGNALING PARTITION INFORMATION FOR 3D LOOKUP TABLE FOR COLOR GAMUT SCALABILITY IN MULTI-LAYER VIDEO CODING

• US 20150229934A1
• Filed: 12/16/2014
• Published: 08/13/2015
• Est. Priority Date: 12/17/2013
• Status: Active Grant

• Current Assignee: Qualcomm, Inc.
• Original Assignee: Qualcomm, Inc.
• Inventors: Li, Xiang, Chen, Jianle, Karczewicz, Marta
• Granted Patent: US 10,531,105 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: H04N 19/105 Selection of the reference unit for prediction within a chosen coding or prediction mode, e.g. adaptive choice of position and number of pixels used for prediction
• CPC Class Codes: H04N 19/124 Quantisation
• CPC Class Codes: H04N 19/136 Incoming video signal characteristics or properties
• CPC Class Codes: H04N 19/186 the unit being a colour or a chrominance component
• CPC Class Codes: H04N 19/29 involving scalability at the object level, e.g. video object layer [VOL]
• CPC Class Codes: H04N 19/30 using hierarchical techniques, e.g. scalability H04N19/63 takes precedence
• CPC Class Codes: H04N 19/31 in the temporal domain
• CPC Class Codes: H04N 19/33 in the spatial domain
• CPC Class Codes: H04N 19/34 Scalability techniques involving progressive bit-plane based encoding of the enhancement layer, e.g. fine granular scalability [FGS]
• CPC Class Codes: H04N 19/42 characterised by implementation details or hardware specially adapted for video compression or decompression, e.g. dedicated software implementation H04N19/635 takes precedence
• CPC Class Codes: H04N 19/44 Decoders specially adapted therefor, e.g. video decoders which are asymmetric with respect to the encoder
• CPC Class Codes: H04N 19/513 Processing of motion vectors
• CPC Class Codes: H04N 19/593 involving spatial prediction techniques
• CPC Class Codes: H04N 19/597 specially adapted for multi-view video sequence encoding
• CPC Class Codes: H04N 19/70 characterised by syntax aspects related to video coding, e.g. related to compression standards

Abstract

Techniques are described for signaling information used to generate three-dimensional (3D) color lookup tables for color gamut scalability in multi-layer video coding. A lower layer of video data may include color data in a first color gamut and a higher layer of the video data may include color data in a second color gamut. To generate inter-layer reference pictures, a video encoder or video decoder performs color prediction using a 3D lookup table to convert the color data of a reference picture in the first color gamut to the second color gamut. According to the techniques, a video encoder may encode partition information and/or color values of a 3D lookup table generated for color gamut scalability. A video decoder may decode the partition information and/or color values to generate the 3D lookup table in order to perform color gamut scalability.

Claims

1. A method of decoding video data, the method comprising:

determining a base partition value for a three-dimensional (3D) lookup table for color gamut scalability;

determining a luma partition value for a luma component of the 3D lookup table;

generating the 3D lookup table with coarser partitioning for chroma components and finer partitioning for the luma component, including;

partitioning each of the luma component, a first chroma component and a second chroma component of the 3D lookup table into a first number of octants based on the base partition value, and

partitioning each of the first number of octants of the luma component into a second number of octants based on the luma partition value;

decoding residual data of video blocks of the video data; and

reconstructing the video blocks of the video data based on the decoded residual data and at least one reference picture generated using the 3D lookup table.

2. The method of claim 1, wherein determining the luma partition value comprises decoding at least one syntax element indicating he luma partition value for the luma component of the 3D lookup table.

4. The method of claim 1, wherein determining the base partition value comprises decoding at least one syntax element indicating the base partition value for the luma component, the first chroma component and the second chroma component of the 3D lookup table.

5. The method of claim 1, wherein determining the base partition value comprises determining the base partition value as a predefined split depth for the luma component, the first chroma component and the second chroma component of the 3D lookup table.

6. The method of claim 1, wherein the coarser partitioning for the chrome components comprises a smaller number of octants in each of the first chrome component and the second chrome component than in the luma component, and the finer partitioning for the luma component comprises a larger number of octant in the luma component than in each of the first chrome component and the second chrome component.

7. The method of claim 1, further comprising, based on at least one of the first chrome component or the second chrome component being partitioned into more than one octant, decoding one or more syntax elements indicating a partitioning boundary for the at least one of the first chrome component or the second chrome component, wherein the partitioning boundary defines an uneven partitioning of the at least one of the first chrome component or the second chrome component into the first number of octants.

8. The method of claim 1, wherein generating the 3D lookup table further includes determining color values for each of the octants of each of the luma component, the first chrome component and the second chrome component.

9. The method of claim 8, wherein the color values comprise values of vertexes of each of the octants, or values of color mapping coefficients of a linear color mapping function for each of the octants.

10. The method of claim 1, further comprising:

performing color prediction using the 3D lookup table to convert color data of a reference picture in a first color gamut for a lower layer of the video data to a second color gamut for a higher layer of the video data; and

generating at least one inter-layer reference picture for the higher layer of the video data based on the converted color data,

wherein reconstructing the video blocks of the video data comprises reconstructing video blocks in a picture of the higher layer of the video data based on the decoded residual data and the at least one inter-layer reference picture generated using the 3D lookup table.

15. The method of claim 1, further comprising determining the base partition value as a predefined split depth for the luma component, the first chroma component and the second chroma component of the 3D lookup table.

3. The method of claim wherein determining the luma partition value comprises deriving the luma partition value for the luma component of the 3D lookup table.

11. A method of encoding video data, the method comprising:

generating a three-dimensional (3D) lookup table for color gamut scalability with coarser partitioning for chroma components and finer partitioning for a luma component, including;

partitioning each of the luma component, a first chroma component and a second chroma component of the 3D lookup table into a first number of octants based on a base partition value for the 3D lookup table, and

partitioning each of the first number of octants of the luma component into a second number of octants based on a luma partition value for the luma component of the 3D lookup table;

predicting video blocks of the video data based on at least one reference picture generated using the 3D lookup table; and

encoding residual data of the video blocks in a bitstream.

12. The method of claim 11, further comprising encoding at least one syntax element indicating the luma partition value for the luma component of the 3D lookup table.

13. The method of claim 11, further comprising deriving the luma partition value for the luma component of the 3D lookup table.

14. The method of claim 11, further comprising encoding at least one syntax element indicating the base partition value for the luma component, the first chroma component and the second chroma component of the 3D lookup table.

16. The method of claim 11, wherein the coarser partitioning for the chroma components comprises a smaller number of octants in each of the first chroma component and the second chroma component than in the luma component, and the finer partitioning for the luma component comprises a larger number of octant in the luma component than in each of the first chroma component and the second chroma component.

17. The method of claim 11, further comprising, based on at least one of the first chroma component or the second chroma component being partitioned into more than one octant, encoding one or more syntax elements indicating a partitioning boundary for the at least one of the first chroma component or the second chroma componen, wherein the partitioning boundary defines an uneven partitioning of the at least one of the first chroma component or the second chroma component into the first number of octants.

18. The method of claim 11, wherein generating the 3D lookup table further includes determining color values for each of the octants of each of the luma component, the first chroma component and the second chroma component.

19. The method of claim 18, wherein the color values comprise values of vertexes of each of the octants, or values of color mapping coefficients of a linear color mapping function for each of the octants.

20. The method of claim 11, further comprising:

performing color prediction using the 3D lookup table to convert color data of a reference picture in a first color gamut for a lower layer of the video data to a second color gamut for a higher layer of the video data; and

generating at least one inter-layer reference picture for the higher layer of the video data based on the converted color data,

wherein predicting the video blocks of the video data comprises predicting video block in a picture of the higher layer of the video data based on the at least one inter-layer reference picture generated using the 3D lookup table.

21. A video decoding device comprising:

a memory configured to store video data; and

one or More processors in communication with the memory and configured to;

determine a base partition value for a three-dimensional (3D) lookup table for color gamut scalability of the video data,

determine a luma partition value for a luma component of the 3D lookup table,

generate the 3D lookup table with coarser partitioning for chroma components and finer partitioning for the luma component, the one or more processors configured to partition each of the luma component, a first chroma component and a second chroma component of the 3D lookup table into a first number of octants based on the base partition value, and partition each of the first number of octants of the lama component into a second number of octants based on the luma partition value,

decode residual data of video blocks of the video data, and

reconstruct the video blocks of the video data based on the decoded residual data and at least one reference picture generated using the 3D lookup table.

22. The device of claim 21, wherein, to determine the luma partition value, the one or More processors are configured to decode at least one syntax element indicating the luma partition value for the luma component of the 3D lookup table.

23. The device of claim 21, wherein, to determine the luma partition value, the one or more processors are configured to derive the luma partition value for the luma component of the 3D lookup table.

24. The device of claim 21, wherein, to determine the base partition value, the one or more processors are configured to decode at least one syntax element indicating the base partition value for the luma component, the first chroma component and the second chroma component of the 3D lookup table.

25. The device of claim 21, wherein, to determine the base partition value, the one or more processors are configured to determine the base partition value as a predefined split depth for the luma component, the first chrome component and the second chroma component of the 3D lookup table.

26. The device of claim 21, wherein the coarser partitioning for the chrome components comprises a smaller number of octants in each of the first chrome component and the second chrome component than in the luma component, and the finer partitioning for the luma component comprises a larger number of octant in the luma component than in each of the first chrome component and the second chrome component.

27. The device of claim 21, wherein, based on at least one of the first chrome component or the second chrome component being partitioned into more than one octant, the one or more processors are configured to decode one or more syntax elements indicating a partitioning boundary for the at least one of the first chrome component or the second chrome component, wherein the partitioning boundary defines an uneven partitioning of the at least one of the first chrome component or the second chrome component into the first number of octants.

28. The device of claim 21, wherein, to generate the 3D lookup table, the one or more processors are further configured to determine color values for each of the octants of each of the luma component, the first chrome component and the second chrome component.

29. The device of claim 28, wherein the color values comprise values of vertexes of each of the octants, or values of color mapping coefficients of a linear color mapping function for each of the octants.

30. The device of claim 21, wherein the one or more processors are configured to:

perform color prediction using the 3D lookup table to convert color data of a reference picture in a first color gamut for a lower layer of the video data to a second color gamut for a higher layer of the video data;

generate at least one inter-layer reference picture for the higher layer of the video data based on the converted color data; and

reconstruct video blocks in a picture of the higher layer of the video data based on the decoded residual data and the at least one inter-layer reference picture generated using the 3D lookup table.

31. A video encoding device comprising:

a memory configured to store video data; and

one or more processors in communication with the memory and configured to;

generate a three-dimensional (3D) lookup table for color gamut scalability of the video data with coarser partitioning for chroma components and finer partitioning for a luma component, the one or more processors configured to partition each of the luma component, a first chroma component and a second chroma component of the 3D lookup table into a first number of octants based on a base partition value, and partition each of the first number of octants of the luma component into a second number of octants based on a luma partition value for the luma component of the 3D lookup table,

predict video blocks of the video data based on at least one reference picture generated using the 3D lookup table, and

encode residual data of the video blocks in a bitstream.

32. The device of claim 31, wherein the one or more processors are configured to encode at least one syntax element indicating the luma partition value for the luma component of the 3D lookup table.

33. The device of claim 31, wherein the one or more processors are configured to derive the luma partition value for the luma component of the 3D lookup table.

34. The device of claim 31, wherein the one or more processors are configured to encode at least one syntax element indicating the base partition value for the luma component, the first chroma component and the second chroma component of the 3D lookup table.

35. The device of claim 31, wherein the one or more processors are configured to determine the base partition value as a predefined split depth for the luma component, the first chroma component and the second chroma component of the 3D lookup table.

36. The device of claim 31, wherein the coarser partitioning for the chroma components comprises a smaller number of octants in each of the first chroma component and the second chroma component than in the luma component, and the finer partitioning for the luma component comprises a larger number of octant in the luma component than in each of the first chroma component and the second chroma component.

37. The device of claim 31, wherein, based on at least one of the first chroma component or the second chroma component being partitioned into more than one octant, the one or more processor are configured to encode one or more syntax elements indicating a partitioning boundary for the at least one of the first chroma component or the second chroma component, wherein the partitioning boundary defines an uneven partitioning of the at least one of the first chroma component or the second chroma component into the first number of octants.

38. The device of claim 31, wherein, to generate the 3D lookup table, the one or more processors are further configured to determine color values for each of the octants of each of the luma component, the first chroma component and the second chroma component.

39. The device of claim 38, wherein the color values comprise values of vertexes of each of the octants, or values of color mapping coefficients of a linear color mapping function for each of the octants.

40. The device of claim 31, wherein the one or more processors are configured to:

perform color prediction using the 3D lookup table to convert color data of a reference picture in a first color gamut for a lower layer of the video data to a second color gamut for a higher layer of the video data;

generate at least one inter-layer reference picture for the higher layer of the video data based on the converted color data; and

predict video blocks in a picture of the higher layer of the video data based on the at least one inter-layer reference picture generated using the 3D lookup table.

41. A video decoding device comprising:

means for determining a base partition value for a three-dimensional (3D) lookup table for color gamut scalability;

means for determining a luma partition value for a luma component of the 3D lookup table;

means for generating the 3D lookup table with coarser partitioning chroma components and finer partitioning for the luma component, including;

means for partitioning each of the luma component, a first chroma component and a second chroma component of the 3D lookup table into a first number of octants based on the base partition value, and

means for partitioning each of the first number of octants of the luma component into a second number of octants based on the luma partition value;

means for decoding residual data of video blocks of the video data; and

means for reconstructing the video blocks of the video data based on the decoded residual data and at least one reference picture generated using the 3D lookup table.

42. A computer-readable storage medium storing instructions for decoding video data that, when executed, cause one or more processors to:

determine a base partition value for a three-dimensional (3D) lookup table for color gamut scalability;

determine a luma partition value for a luma component of the 3D lookup table;

generate the 3D lookup table with coarser partitioning for chroma components and finer partitioning for the luma component, the instructions cause the one or more processors to;

partition each of the luma component, a first chroma component and a second chroma component of the 3D lookup table into a first number of octants based on the base partition value, and

partition each of the first number of octants of the luma component into a second number of octants based on the luma partition value;

decode residual data of video blocks of the video data; and

reconstruct the video blocks of the video data based on the decoded residual data and at least one reference picture generated using the 3D lookup table.