Method and device for luma mapping with cross component scaling

Patent metadata

Field	Value
Publication number	US-12301880-B2
Application number	US-202118269506-A
Country	US
Kind code	B2
Filing date	Dec 3, 2021
Priority date	Dec 23, 2020
Publication date	May 13, 2025
Grant date	May 13, 2025

Abstract

A method comprising: obtaining ( 601 ) a syntax element associated with video data, wherein said syntax element specifies that a cross-color component transform process in which at least one second color component is transformed based on at least one first color component different from the second color component is to be applied to the video data as a post processing process following a decoding process to be applied to the video data.

First claim

The invention claimed is:

1. A method comprising:
obtaining an information set associated with video data, each sample of each picture represented by the video data being represented by a plurality of color components, wherein said information set comprises a syntax element indicating with a first value that a first transform mapping values of a first color component from a first dynamic range to a second dynamic range is explicitly signaled in the information set and, with a second value, that the first transform is inferred from a second transform signaled in the information set mapping values of a second color component from a third dynamic range to a fourth dynamic range; and,
decoding the video data based on the syntax element.

2. The method of claim 1 wherein, the first color component is a chroma component and the second color component is a luma component.

3. The method according to claim 1 wherein the first transform is a cross component transform mapping values of the first color component from the first dynamic range to the second dynamic range based on the second color component.

4. The method of claim 1 wherein, responsive to the syntax element having the second value, the first transform is derived from information representative of a slope of the second transform.

5. The method of claim 1 wherein the first color component is a first chroma component and the second color component is a second chroma component.

6. The method of claim 1 wherein, responsive to the syntax element having the second value, the first transform is derived from the second transform by adding difference values signaled in the information set for the first transform to information representing the second transform signaled in the information set.

7. A method comprising:
signaling an information set associated with video data, each sample of each picture represented by the video data being represented by a plurality of color components, wherein said information set comprises a syntax element indicating with a first value that a first transform mapping values of a first color component from a first dynamic range to a second dynamic range is explicitly signaled in the information set and, with a second value, that the first transform is inferred from a second transform signaled in the information set mapping values of a second color component from a third dynamic range to a fourth dynamic range.

8. The method of claim 7 wherein, the first color component is a chroma component and the second color component is a luma component.

9. The method according to claim 7 wherein the first transform is a cross component transform mapping values of the first color component from the first dynamic range to the second dynamic range based on the second color component.

10. The method of claim 7 wherein, responsive to the syntax element having the second value, the first transform is derived from information representative of a slope of the second transform.

11. The method of claim 7 wherein the first color component is a first chroma component and the second color component is a second chroma component.

12. The method of claim 7 wherein, responsive to the syntax element having the second value, the first transform is derived from the second transform by adding difference values signaled in the information set for the first transform to information representing the second transform signaled in the information set.

13. A device comprising electronic circuitry configured for:
obtaining an information set associated with video data, each sample of each picture represented by the video data being represented by a plurality of color components, wherein said information set comprises a syntax element indicating with a first value that a first transform mapping values of a first color component from a first dynamic range to a second dynamic range is explicitly signaled in the information set and, with a second value, that the first transform is inferred from a second transform signaled in the information set mapping values of a second color component from a third dynamic range to a fourth dynamic range; and,
decoding the video data based on the syntax element.

14. The device of claim 13 wherein, the first color component is a chroma component and the second color component is a luma component.

15. The device according to claim 13 wherein the first transform is a cross component transform mapping values of the first color component from the first dynamic range to the second dynamic range based on the second color component.

16. The device of claim 13 wherein, responsive to the syntax element having the second value, the first transform is derived from information representative of a slope of the second transform.

17. The device of claim 13 wherein the first color component is a first chroma component and the second color component is a second chroma component.

18. The device of claim 13 wherein, responsive to the syntax element having the second value, the first transform is derived from the second transform by adding difference values signaled in the information set for the first transform to information representing the second transform signaled in the information set.

19. A device comprising electronic circuitry configured for:
signaling an information set associated with video data, each sample of each picture represented by the video data being represented by a plurality of color components, wherein said information set comprises a syntax element indicating with a first value that a first transform mapping values of a first color component from a first dynamic range to a second dynamic range is explicitly signaled in the information set and, with a second value, that the first transform is inferred from a second transform signaled in the information set mapping values of a second color component from a third dynamic range to a fourth dynamic range.

20. The device of claim 19 wherein, the first color component is a chroma component and the second color component is a luma component.

Assignees

• Interdigital Ce Patent Holdings Sas

Inventors

• Francois Edouard
• Bordes Philippe
• Andrivon Pierre
• De Lagrange Philippe
• Martin-Cocher Gaëlle
• Gudumasu Srinivas

Classifications

• H04N19/12

  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 title

• H04N19/186

  the unit being a colour or a chrominance component · CPC title

• H04N19/176

  the region being a block, e.g. a macroblock · CPC title

• H04N19/117 Primary

  Filters, e.g. for pre-processing or post-processing (sub-band filter banks H04N19/635) · CPC title

• H04N19/85 Primary

  using pre-processing or post-processing specially adapted for video compression · CPC title