US-12627790-B2 - Harmonized local illumination compensation and modified inter coding tools

Abstract

A method for video processing is provided to include: determining, based on an inheritance rule, whether to use a local illumination compensation (LIC) mode for a conversion between a current block of a video region of a video and a coded representation of the video, and performing the conversion based on the determining. The LIC mode includes using a linear model of illumination changes in the current block during the conversion. The inheritance rule specifies to inherit a use of the LIC mode from a base merge candidate of an ultimate motion vector expression (UMVE) mode, and the UMVE mode includes using a motion vector expression that includes a base merge candidate and motion vector differences utilized to refine the motion information of the base merge candidate.

Inventors

• Hongbin Liu
• Li Zhang
• Kai Zhang
• Yue Wang

Assignees

• BEIJING BYTEDANCE NETWORK TECHNOLOGY CO., LTD.
• BYTEDANCE INC.

Dates

Publication Date

20260512

Application Date

20230725

Priority Date

20181023

Claims (19)

1. 1 . A method for video processing, comprising: performing a conversion between a current block of a video and a bitstream of the video according to a rule specifying interaction between a local illumination compensation (LIC) tool and other coding modes, wherein the interaction comprises: using the LIC tool together with intra block copy (IBC) mode for the conversion, or using the LIC tool and generalized bi-prediction (GBI) mode exclusive of each other for the conversion, or using the LIC tool together with multi-hypothesis prediction mode for the conversion, or inheriting an LIC flag from a base merge candidate in ultimate motion vector expression (UMVE) mode, wherein LIC parameters are derived implicitly, and wherein the LIC flag is signaled explicitly in the UMVE mode.
2. 2 . The method of claim 1 , wherein when the current block is coded with the IBC mode, a flag indicating a usage of the LIC tool is signaled, or when the current block is coded with the LIC tool, a flag indicating the usage of the IBC mode is signaled.
3. 3 . The method of claim 1 , wherein in a merge mode, when the current block is coded with the IBC mode and the current block inherits motion information from a neighboring block, the current block inherits a flag indicating a usage of the LIC tool from the neighboring block, or the current block inherits LIC parameters from the neighboring block.
4. 4 . The method of claim 1 , wherein when a flag indicating a usage of the LIC tool has a value of true, a syntax element indicating a usage of the GBI mode is not signaled, or when the syntax element indicating a usage of the GBI mode has a value of true, the flag indicating a usage of the LIC tool is not signaled.
5. 5 . The method of claim 1 , further comprising checking whether the LIC tool or the GBI mode are enabled in a certain order, and terminating the checking when one of the LIC tool and the GBI mode is enabled.
6. 6 . The method of claim 1 , wherein an LIC flag is explicitly signaled for multi-hypothesis advanced motion vector prediction (AMVP) mode and merge mode.
7. 7 . The method of claim 6 , wherein the explicitly signaled LIC flag is applied to both AMVP mode and the merge mode, or the explicitly signaled LIC flag is applied only to the AMVP mode, while a LIC flag for the merge mode is inherited from a corresponding merge candidate, and different LIC flags are used for AMVP mode and merge mode, and different LIC parameters are derived or inherited for the AMVP mode and the merge mode, or the LIC flag is not signaled and LIC is always disabled for AMVP mode, for merge mode, LIC flag or LIC parameter is inherited or derived, or the LIC tool is disabled for the merge mode.
8. 8 . The method of claim 1 , wherein LIC flags are inherited from the corresponding merge candidates for multi-hypothesis merge mode, and wherein: different LIC flags are inherited for each of two selected merge candidates, and different LIC parameters are derived/inherited for the two selected merge candidates, or a LIC flag is only inherited for a first selected merge candidate and the LIC tool is always disabled for a second selected merge candidate.
9. 9 . The method of claim 1 , wherein a LIC flag is explicitly signaled for multi-hypothesis inter prediction mode, and when the current block is predicted with merge mode or the UMVE mode and additional motion information: the explicitly signaled LIC flag is applied to both the merge mode or the UMVE mode and the additional motion information, or the explicitly signaled LIC flag is applied to the additional motion information, and the merge mode, a LIC flag or LIC parameters is inherited or derived, or the LIC flag is not signaled and disabled for the additional motion information, and the merge mode, LIC flag or LIC parameter is inherited or derived.
10. 10 . The method of claim 9 , wherein when the current block is predicted with AMVP mode and the additional motion information, the explicitly signaled LIC flag is applied to both the AMVP mode and the additional motion information.
11. 11 . The method of claim 9 , wherein different LIC parameters are derived or inherited for the merge mode, the UMVE mode, AMVP mode, and the additional motion information.
12. 12 . The method of claim 1 , wherein when the multi-hypothesis prediction mode is applied to the current block, the LIC tool is applied to less than all prediction signals of the current block.
13. 13 . The method of claim 1 , wherein when the multi-hypothesis prediction mode is applied to the current block, a plurality of flags are signaled or derived to indicate a usage of the LIC tool.
14. 14 . The method of claim 1 , wherein LIC parameters are derived implicitly for a boundary block coded in the UMVE mode, or LIC parameters are inherited from the base merge candidate for an inner block coded in the UMVE mode.
15. 15 . The method of claim 1 , wherein the performing of the conversion includes encoding the current block into the bitstream.
16. 16 . The method of claim 1 , wherein the performing of the conversion includes decoding the current block from the bitstream.
17. 17 . An apparatus in a video system comprising a processor and a non-transitory memory with instructions thereon, wherein the instructions upon execution by the processor, cause the processor to: perform a conversion between a current block of a video and a bitstream of the video according to a rule specifying interaction between a local illumination compensation (LIC) tool and other coding modes, wherein the interaction comprises: using the LIC tool together with intra block copy (IBC) mode for the conversion, or using the LIC tool and generalized bi-prediction (GBI) mode exclusive of each other for the conversion, or using the LIC tool together with multi-hypothesis prediction mode for the conversion, or inheriting an LIC flag from a base merge candidate in ultimate motion vector expression (UMVE) mode, wherein LIC parameters are derived implicitly, and wherein the LIC flag is signaled explicitly in the UMVE mode.
18. 18 . A non-transitory computer-readable storage medium storing instructions that cause a processor to: perform a conversion between a current block of a video and a bitstream of the video according to a rule specifying interaction between a local illumination compensation (LIC) tool and other coding modes, wherein the interaction comprises: using the LIC tool together with intra block copy (IBC) mode for the conversion, or using the LIC tool and generalized bi-prediction (GBI) mode exclusive of each other for the conversion, or using the LIC tool together with multi-hypothesis prediction mode for the conversion, or inheriting an LIC flag from a base merge candidate in ultimate motion vector expression (UMVE) mode, wherein LIC parameters are derived implicitly, and wherein the LIC flag is signaled explicitly in the UMVE mode.
19. 19 . A non-transitory computer-readable recording medium storing a bitstream of a video which is generated by a method performed by a video processing apparatus, wherein the method comprises: generating the bitstream of the video according to a rule specifying interaction between a local illumination compensation (LIC) tool and other coding modes, wherein the interaction comprises: using the LIC tool together with intra block copy (IBC) mode for the generating, or using the LIC tool and generalized bi-prediction (GBI) mode exclusive of each other for the generating, or using the LIC tool together with multi-hypothesis prediction mode for the generating, or inheriting an LIC flag from a base merge candidate in ultimate motion vector expression (UMVE) mode, wherein LIC parameters are derived implicitly, and wherein the LIC flag is signaled explicitly in the UMVE mode.

Description

CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation of U.S. application Ser. No. 17/230,075, filed on Apr. 14, 2021, which is a continuation of International Application No. PCT/IB2019/059050, filed on Oct. 23, 2019, which claims the priority to and benefits of International Patent Application No. PCT/CN2018/111436, filed on Oct. 23, 2018, and PCT/CN2019/071759, filed on Jan. 15, 2019. All the aforementioned patent applications are hereby incorporated by reference in their entireties. TECHNICAL FIELD The present patent document relates to the field of video coding. BACKGROUND Currently, efforts are underway to improve the performance of current video codec technologies to provide better compression ratios or provide video coding and decoding schemes that allow for lower complexity or parallelized implementations. Industry experts have recently proposed several new video coding tools and tests are currently underway for determining their effectivity. SUMMARY The present document provides techniques for incorporating local illumination compensation in embodiments of video encoders or decoders. In one example aspect, a method of video processing is disclosed. A video processing method is provided to comprise determining, for a conversion between a current block of a current video picture of a video and a coded representation of the video, that both a local illumination compensation (LIC) tool and an intra block copy (IBC) tool are enabled for the conversion of the current block, and performing the conversion based on the determining. The LIC tool uses a linear model of illumination changes in the current block during the conversion, and the IBC tool uses a portion of the current video picture for the conversion of the current block. In another example aspect, a method of video processing is disclosed. determining to use a rule that specifies to use a local illumination compensation (LIC) tool exclusive with a current picture referencing (CPR) mode for a conversion between a current block of a video and a coded representation of the video; and performing the conversion based on the determining. The LIC tool includes using a linear model of illumination changes in the current block during the conversion, and the CPR mode includes using another portion of a current picture comprising the current block for a prediction of the current block. In another example aspect, a method of video processing is disclosed. The video processing method comprises: performing a determination, for a conversion between a current block of a video and a coded representation of the video, that a generalized bi prediction (GBI) tool or a multi-hypothesis inter prediction tool is enabled for the conversion or a local illumination compensation (LIC) tool being enabled for the conversion, and performing the conversion based on the determination, wherein the LIC tool includes using a linear model of illumination changes in the current block during the conversion. In another example aspect, a method of video processing is disclosed. The video processing method comprises: determining to use a local illumination compensation (LIC) tool with a multi-hypothesis prediction tool for a conversion between a current block of a video and a coded representation of the video; and performing the conversion based on the determining, wherein the LIC tool includes using a linear model of illumination changes in the current block during the conversion. In another example aspect, a method of video processing is disclosed. The video processing method comprises: determining to use a local illumination compensation (LIC) tool and a weighted prediction tool exclusive of each other for a conversion between a current block and a coded representation of the current block; and performing the conversion based on the determining, wherein the LIC tool includes using a linear model of illumination changes in the current block during the conversion. In another example aspect, a method of video processing is disclosed. The method comprises: determining, based on an inheritance rule, whether to use a local illumination compensation (LIC) mode for a conversion between a current block of a video region of a video and a coded representation of the video, and performing the conversion based on the determining. The LIC mode includes using a linear model of illumination changes in the current block during the conversion. The inheritance rule specifies to inherit a use of the LIC mode from a base merge candidate of an ultimate motion vector expression (UMVE) mode, and the UMVE mode comprises using a motion vector expression that includes a base merge candidate and motion vector differences utilized to refine the motion information of the base merge candidate. In another example aspect, a method of video processing is disclosed. The method comprises: determining to use a local illumination compensation (LIC) tool and a sub-block based coding mode exclusive of