Chroma residual scaling foreseeing a corrective value to be added to luma mapping slope values

Patent metadata

Field	Value
Publication number	US-12238304-B2
Application number	US-202017760702-A
Country	US
Kind code	B2
Filing date	Sep 16, 2020
Priority date	Sep 17, 2019
Publication date	Feb 25, 2025
Grant date	Feb 25, 2025

Abstract

At least a method and an apparatus are presented for efficiently encoding or decoding video. For example, one or more chroma residual scaling parameters are determined based one or more luma mapping parameters and based on a corrective value of the one or more chroma residual scaling parameters. The video is encoded or decoded based on the determined one or more chroma residual scaling parameters.

First claim

The invention claimed is:

1. A method comprising:
determining one or more chroma residual scaling parameters based on one or more luma mapping parameters and based on a corrective value of the one or more chroma residual scaling parameters, wherein the one or more luma mapping parameters are representative of a slope of a luma forward mapping function applied to a prediction of luma samples, and wherein the corrective value of the one or more chroma residual scaling parameters is an additive value to be added to the one or more luma mapping parameters to modify the slope of the luma forward mapping function; and
encoding the video based on the determined one or more chroma residual scaling parameters.

2. The method of claim 1 , wherein said corrective value of the one or more chroma residual scaling parameters is signaled as adaptive parameter in an Adaptation Parameter Set (APS).

3. The method of claim 1 , wherein the chroma residual scaling parameters are derived by inverting corrected luma mapping slope values resulting from adding the corrective value of the one or more chroma residual scaling parameters to the one or more luma mapping parameters.

4. The method of claim 3 , wherein the corrective value of the one or more chroma residual scaling parameters is in a range [−7, 7].

5. The method of claim 4 , wherein the corrected luma mapping slope values are bounded.

6. A method comprising:
determining one or more chroma residual scaling parameters based on one or more luma mapping parameters and based on a corrective value of the one or more chroma residual scaling parameters, wherein the one or more luma mapping parameters are representative of a slope of a luma forward mapping function applied to a prediction of luma samples and wherein the corrective value of the one or more chroma residual scaling parameters is an additive value to be added to the one or more luma mapping parameters to modify the slope of the luma forward mapping function; and
decoding the video based on the determined one or more chroma residual scaling parameters.

7. The method of claim 6 , wherein said corrective value of the one or more chroma residual scaling parameters is signaled as adaptive parameter in an Adaptation Parameter Set (APS).

8. The method of claim 6 , wherein the chroma residual scaling parameters are derived by inverting corrected luma mapping slope values resulting from adding the corrective value of the one or more chroma residual scaling parameters to the one or more luma mapping parameters.

9. The method of claim 8 , wherein the corrective value of the one or more chroma residual scaling parameters is in a range [−7, 7].

10. The method of claim 9 , wherein the corrected luma mapping slope values are bounded.

11. An apparatus comprising one or more processors, wherein the one or more processors are configured to:
determine one or more chroma residual scaling parameters based on one or more luma mapping parameters and based on a corrective value of the one or more chroma residual scaling parameters, wherein the one or more luma mapping parameters are representative of a slope of a luma forward mapping function applied to a prediction of luma samples and wherein the corrective value of the one or more chroma residual scaling parameters is an additive value to be added to the one or more luma mapping parameters to modify the slope of the luma forward mapping function; and
encode the video based on the determined one or more chroma residual scaling parameters.

12. The apparatus of claim 11 , wherein said corrective value of the one or more chroma residual scaling parameters is signaled as adaptive parameter in an Adaptation Parameter Set (APS).

13. The apparatus of claim 11 , wherein the chroma residual scaling parameters are derived by inverting corrected luma mapping slope values resulting from adding the corrective value of the one or more chroma residual scaling parameters to the one or more luma mapping parameters.

14. The apparatus of claim 13 , wherein the corrective value of the one or more chroma residual scaling parameters is in a range [−7, 7].

15. The apparatus of claim 14 , wherein the corrected luma mapping slope values are bounded.

16. An apparatus comprising one or more processors, wherein the one or more processors are configured to:
determine one or more chroma residual scaling parameters based on one or more luma mapping parameters and based on a corrective value of the one or more chroma residual scaling parameters, wherein the one or more luma mapping parameters are representative of a slope of a luma forward mapping function applied to a prediction of luma samples and wherein the corrective value of the one or more chroma residual scaling parameters is an additive value to be added to the one or more luma mapping parameters to modify the slope of the luma forward mapping function; and
decode the video based on the determined one or more chroma residual scaling parameters.

17. The apparatus of claim 16 , wherein said corrective value of the one or more chroma residual scaling parameters is signaled as adaptive parameter in an Adaptation Parameter Set (APS).

18. The apparatus of claim 16 , wherein the chroma residual scaling parameters are derived by inverting corrected luma mapping slope values resulting from adding the corrective value of the one or more chroma residual scaling parameters to the one or more luma mapping parameters.

19. The apparatus of claim 18 , wherein the corrective value of the one or more chroma residual scaling parameters is in a range [−7, 7].

20. The apparatus of claim 19 , wherein the corrected luma mapping slope values are bounded.

21. A non-transitory computer readable medium having stored instructions which, when executed by one or more processors, cause the one or more processors to perform a method using a corrective value for one or more chroma residual scaling parameters, the non-transitory computer readable medium further comprising containing data content encoded thereupon, comprising:
a coded block;
one or more luma mapping parameters representative of a slope of a luma forward mapping function applied to a prediction of luma samples of the coded block; and the corrective value for one or more chroma residual scaling parameters, wherein the corrective value of the one or more chroma residual scaling parameters is an additive value to be added to the one or more luma mapping parameters to modify the slope of the luma forward mapping function to produce chroma residual scaling parameters representative of a chroma scaling function applied to a prediction of chroma samples of the coded block.

Assignees

• Interdigital Madison Patent Holdings Sas

Inventors

• Francois Edouard
• GALPIN Franck
• Naser Karam
• De Lagrange Philippe

Classifications

• H04N19/82

  involving filtering within a prediction loop · CPC title

• H04N19/36

  Scalability techniques involving formatting the layers as a function of picture distortion after decoding, e.g. signal-to-noise [SNR] scalability · CPC title

• H04N19/65

  using error resilience · CPC title

• H04N19/132

  Sampling, masking or truncation of coding units, e.g. adaptive resampling, frame skipping, frame interpolation or high-frequency transform coefficient masking · CPC title

• H04N19/70

  characterised by syntax aspects related to video coding, e.g. related to compression standards · CPC title