Illumination Compensation Status Derivation in Video Coding
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Solution Overview
Problem
Current video coding techniques face challenges in efficiently compensating for illumination variations between pictures, which affects compression efficiency and quality, particularly in inter-view prediction and illumination compensation.
Innovation Solution
The implementation of illumination compensation (IC) techniques in video coding systems, where IC parameters are derived and signaled in the bitstream to adjust for illumination discrepancies, allowing for more effective compression and decoding of video data across varying brightness levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If illumination compensation parameters are explicitly signaled in the bitstream, then illumination compensation accuracy is improved, but bitrate increases
Solution Approach 1:
The decoder derives illumination compensation parameters autonomously from the bitstream without requiring explicit signaling of these parameters. The decoder uses the pic_ic_enabled_flag and pic_reset_ic_flag to control the derivation process, allowing the system to self-determine illumination compensation status and parameters, thereby reducing bitrate while maintaining compensation accuracy
Solution Approach 2:
The patent extracts only the essential control flags (pic_ic_enabled_flag, pic_reset_ic_flag) from the full illumination compensation parameter set, transmitting only these minimal necessary elements in the bitstream while deriving the actual compensation parameters at the decoder side, thus reducing transmitted data volume while preserving compensation functionality
2Reliability
If illumination compensation is applied to all blocks, then video quality is improved, but computational complexity increases
Solution Approach 1:
The patent applies illumination compensation selectively at the picture level using pic_ic_enabled_flag to enable or disable IC for specific pictures, and pic_reset_ic_flag to reset compensation status. This localized control approach applies compensation only where and when needed, improving video quality in affected regions while avoiding unnecessary computational overhead in regions where compensation is not required
Data Source
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AI summary
Techniques and systems are provided for coding video data. For example, a method of coding video data includes determining motion information for a current block and determining an illumination compensation status for the current block. The method further includes coding the current block based on the motion information and the illumination compensation status for the current block. In some examples, the method further includes determining the motion information for the current block based on motion information of a candidate block. In such examples, the method further includes determining an illumination compensation status of the candidate block and deriving the illumination compensation status for the current block based on the illumination compensation status of the candidate block.