Local illumination compensation with multiple linear models

Patent metadata

Field	Value
Publication number	US-12470697-B2
Application number	US-202218722307-A
Country	US
Kind code	B2
Filing date	Dec 19, 2022
Priority date	Dec 21, 2021
Publication date	Nov 11, 2025
Grant date	Nov 11, 2025

Abstract

Systems, methods, and instrumentalities are disclosed for performing local illumination compensation (LIC) with multiple linear models. In an example, a device, such as a video decoding device, or a video encoding device, may determine that sub-partition-based local illumination compensation (sub-LIC) is enabled for a current block. The device may divide the current block into a plurality of sub-partitions. The device may identify a plurality of templates associated with the plurality of sub-partitions. The device may derive a plurality of local illumination compensation (LIC) parameter sets associated with the plurality of sub-partitions based on the plurality of templates associated with the plurality of sub-partitions. The device may process (e.g., encode and/or decode) the current block based on the plurality of LIC parameter sets.

First claim

What is claimed:

1 . A video decoding device, comprising:
a processor configured to:
determine that sub-partition-based local illumination compensation (sub-LIC) is enabled for a current block;
divide the current block into a first sub-partition and a second sub-partition;
identify a first template associated with the first sub-partition;
derive a first local illumination compensation (LIC) parameter set based on the first template associated with the first sub-partition;
identify a second template associated with the second sub-partition;
derive a second LIC parameter set based on the second template associated with the second sub-partition;
apply the first LIC parameter set on a reference block of the current block to obtain a first prediction block of the current block;
apply the second LIC parameter set on the reference block of the current block to obtain a second prediction block of the current block; and
decode the current block based on the first prediction block and the second prediction block.

2 . The device of claim 1 , the processor further configured to:
obtain a sub-LIC enablement indicator configured to indicate whether sub-LIC is enabled for the current block, wherein that sub-LIC is enabled for the current block is determined based on the sub-LIC enablement indicator indicating that sub-LIC is enabled for the current block.

3 . The device of claim 1 , the processor further configured to:
determine whether a sub-LIC direction indication is included in video data based on a sub-LIC enablement indicator; and based on the sub-LIC enablement indicator indicating that sub-LIC is enabled, obtain the sub-LIC direction indication from the video data, wherein the current block is divided into the first sub-partition and the second sub-partition based on the sub-LIC direction indication.

4 . The device of claim 1 , wherein the first template corresponds to a left sub-partition of the current block, and the first template comprises reconstructed samples neighboring a left border and a top border of the left sub-partition of the current block, and the second template corresponds to a right sub-partition of the current block, and the second template comprises reconstructed samples neighboring a top border of the right sub-partition of the current block.

5 . The device of claim 1 , wherein the first template corresponds to a top sub-partition of the current block, and the first template comprises reconstructed samples neighboring a left border and a top border of the top sub-partition of the current block, and the second template corresponds to a bottom sub-partition of the current block, and the second template comprises reconstructed samples neighboring a left border of the bottom sub-partition of the current block.

6 . The device of claim 1 , wherein the processor is further configured to:
apply the first LIC parameter set on a plurality of reference samples of the first sub-partition to obtain a plurality of prediction samples of the first sub-partition; apply the second LIC parameter set on a plurality of reference samples of the second sub-partition to obtain a plurality of prediction samples of the second sub-partition; and obtain a prediction block of the current block by combining the plurality of prediction samples of the first sub-partition and the plurality of prediction samples of the second sub-partition, the current block being decoded based on the prediction block.

7 . A method for video decoding, the method comprising:
determining that sub-partition-based local illumination compensation (sub-LIC) is enabled for a current block; dividing the current block into a first sub-partition and a second sub-partition; identifying a first template associated with the first sub-partition; deriving a first local illumination compensation (LIC) parameter set based on the first template associated with the first sub-partition; identifying a second template associated with the second sub-partition; deriving a second LIC parameter set based on the second template associated with the second sub-partition; applying the first LIC parameter set on a reference block of the current block to obtain a first prediction block of the current block; applying the second LIC parameter set on the reference block of the current block to obtain a second prediction block of the current block; and decoding the current block based on the first prediction block and the second prediction block.

8 . The method of claim 7 , the method further comprising:
obtaining a sub-LIC enablement indicator configured to indicate whether sub-LIC is enabled for the current block, wherein that sub-LIC is enabled for the current block is determined based on the sub-LIC enablement indicator indicating that sub-LIC is enabled for the current block.

9 . The method of claim 7 , the method further comprising:
determining whether a sub-LIC direction indication is included in video data based on a sub-LIC enablement indicator; and based on the sub-LIC enablement indicator indicating that sub-LIC is enabled, obtaining the sub-LIC direction indication from the video data, wherein the current block is divided into the first sub-partition and the second sub-partition based on the sub-LIC direction indication.

10 . The method of claim 7 , wherein the first template corresponds to a left sub-partition of the current block, and the first template comprises reconstructed samples neighboring a left border and a top border of the left sub-partition of the current block, and the second template corresponds to a right sub-partition of the current block, and the second template comprises reconstructed samples neighboring a top border of the right sub-partition of the current block.

11 . The method of claim 7 , wherein the first template corresponds to a top sub-partition of the current block, and the first template comprises reconstructed samples neighboring a left border and a top border of the top sub-partition of the current block, and the second template corresponds to a bottom sub-partition of the current block, and the second template comprises reconstructed samples neighboring a left border of the bottom sub-partition of the current block.

12 . The method of claim 7 , wherein the method further comprises:
applying the first LIC parameter set on a plurality of reference samples of the first sub-partition to obtain a plurality of prediction samples of the first sub-partition; applying the second LIC parameter set on a plurality of reference samples of the second sub-partition to obtain a plurality of prediction samples of the second sub-partition; and obtaining a prediction block of the current block by combining the plurality of prediction samples of the first sub-partition and the plurality of prediction samples of the second sub-partition, the current block being decoded based on the prediction block.

13 . A video encoding device, comprising:
a processor configured to:
determine to enable sub-partition-based local illumination compensation (sub-LIC) for a current block;
divide the current block into a first sub-partition and a second sub-partition;
identify a first template associated with the first sub-partition;
derive a first local illumination compensation (LIC) parameter set based on the first template associated with the first sub-partition;
identify a second template associated with the second sub-partition;
derive a second LIC parameter set based on the second template associated with the second sub-partition;
apply the first LIC parameter set on a reference block of the current block to obtain a first prediction block of

Assignees

• Interdigital Ce Patent Holdings Sas

Inventors

• Chen Ya
• Bordes Philippe
• Robert Antoine
• Naser Karam

Classifications

• H04N19/196

  being specially adapted for the computation of encoding parameters, e.g. by averaging previously computed encoding parameters (processing of motion vectors H04N19/513) · CPC title

• H04N19/176

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

• H04N19/167

  Position within a video image, e.g. region of interest [ROI] · 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

• H04N19/119

  Adaptive subdivision aspects, e.g. subdivision of a picture into rectangular or non-rectangular coding blocks · CPC title