Chroma Block Vector Derivation from Luma for Video Coding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing video coding and decoding standards face challenges in efficiently coding and decoding chroma blocks, often resulting in information loss and suboptimal coding performance due to separate coding of chroma and luma blocks.
Innovation Solution
A method and apparatus for video coding and decoding that derive a block vector (BV) of a chroma block from a BV of a corresponding luma block, allowing for partitioning, acquisition, mapping, and decoding of chroma blocks based on the derived BV, thereby improving coding efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If chroma blocks and luma blocks are coded separately, then coding flexibility is improved, but coding performance deteriorates and information loss increases
Solution Approach 1:
The patent merges the coding processes of chroma blocks and luma blocks by deriving chroma block vectors from luma block vectors. This integration allows the system to leverage the strong correlation between chroma and luma components, reducing information loss while maintaining coding flexibility through the unified vector derivation approach.
Solution Approach 2:
The patent introduces an intermediary mechanism where luma block vectors serve as mediators to derive chroma block vectors. This intermediary approach enables indirect coding where chroma information is inferred from luma information, reducing direct information loss while preserving coding adaptability.
2Ease of operation
If chroma blocks are coded separately, then processing independence is improved, but coding performance deteriorates
Solution Approach 1:
The patent applies preliminary action by pre-establishing the derivation relationship between luma block vectors and chroma block vectors. This allows the system to maintain processing independence for separate block types while achieving improved coding performance through the pre-defined vector derivation mechanism that leverages luma information for chroma coding.
3Ease of manufacture
If separate coding is used for chroma and luma, then implementation simplicity is improved, but coding efficiency deteriorates
Solution Approach 1:
The patent changes the parameter approach by transforming separate coding parameters into a unified vector derivation system. The luma block vector serves as a parameter that can be reused to derive chroma block vectors, improving coding efficiency while maintaining implementation simplicity through the standardized derivation process.
Data Source
AI summary
A video decoding method, includes: partitioning a chroma block into at least one chroma sub-block based on determining a first block vector (BV) of the chroma block is derived from a second BV of a luma block; acquiring a third BV of a first luma sub-block corresponding to the at least one chroma sub-block; mapping the third BV to a fourth BV of the at least one chroma sub-block according to a chroma scale factor of video to be decoded; and decoding the chroma block according to the fourth BV to obtain a reconstructed block corresponding to the chroma block.