Local Illumination Compensation for Video Block Boundary Processing
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Solution Overview
Problem
Current video coding technologies face challenges in achieving optimal compression ratios and complexity reduction, particularly in handling illumination changes across video frames, which affects encoding efficiency and decoding complexity.
Innovation Solution
The implementation of local illumination compensation (LIC) techniques in video encoders and decoders, using a linear model for illumination changes, specifically enabling LIC for blocks on boundaries and disabling it for interior blocks, and deriving LIC parameters from neighboring samples to adjust pixel values accordingly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If LIC tool is enabled for all blocks in video region, then illumination compensation quality improves, but decoding complexity increases
Solution Approach 1:
The patent applies local quality by enabling LIC selectively only for boundary blocks rather than all blocks. The position rule determines that LIC is applied based on the block's location within the video region, applying different processing quality to different spatial locations. This resolves the contradiction by providing high illumination compensation quality where needed (boundaries) while avoiding unnecessary complexity in interior blocks.
2Measurement precision
If LIC operation is performed for all pixels in current block, then compensation accuracy improves, but processing time increases
Solution Approach 1:
The patent applies partial action by performing LIC operation only for less than all pixels in the current block. Specifically, it processes only boundary pixels or selected pixels based on the position rule, rather than applying the illumination compensation to every pixel. This reduces processing time while maintaining sufficient compensation accuracy for the most critical regions.
3Productivity
If multiple coding tools are used for current block, then compression performance improves, but encoding complexity increases
Solution Approach 1:
The patent applies partial action by limiting the use of multiple coding tools to only boundary blocks. The position rule ensures that complex tools like LIC and CIIP are applied selectively rather than uniformly to all blocks. This maintains high compression performance for boundary regions while reducing overall encoding complexity by avoiding redundant processing in interior blocks.
Data Source
AI summary
A video processing method is provided to include: determining, based on a position rule, whether a local illumination compensation (LIC) tool is enabled for a conversion between a current block in a video region of a video and a coded representation of the video, and performing the conversion based on the position rule. The position rule specifies that the LIC tool is enabled for blocks on boundaries of the video region and disabled for blocks inside the video region and the LIC tool includes using a linear model of illumination changes in the current block during the conversion.