Cross-Component Chroma Prediction With Conditional Syntax Signaling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing video coding standards, such as H.266/VVC, incur additional bit overhead due to incomplete consideration in chroma prediction modes, particularly in cross-component prediction modes, leading to reduced coding efficiency.
Innovation Solution
A method is introduced to determine mode enable information for a current block, specifically when a weighted chroma fusion mode is used, and only encode the first syntax flag information if the chroma fusion merge mode is enabled, constructing a parameter candidate list to derive a model parameter for cross-component prediction, thereby reducing unnecessary bit overhead.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If chroma fusion merge mode is always encoded with first syntax flag information, then prediction accuracy is improved, but bit overhead increases
Solution Approach 1:
The patent applies dynamics by making the encoding of first syntax flag information conditional rather than fixed. The flag is only encoded when chroma fusion merge mode is actually used, allowing the system to adapt between detailed mode specification and simplified processing based on actual usage needs, thus balancing prediction accuracy with bit overhead
Solution Approach 2:
The patent changes the parameter of syntax flag encoding from a static requirement to a dynamic conditional requirement. By modifying the encoding behavior based on the mode type (only encoding when needed), the system optimizes the bit stream length while maintaining prediction accuracy for cases where the mode is actually utilized
2Adaptability or versatility
If first syntax flag information is always encoded, then mode selection flexibility is improved, but coding efficiency decreases
Solution Approach 1:
The patent applies partial action by encoding the first syntax flag information only when necessary (when chroma fusion merge mode is used), rather than always encoding it. This selective encoding maintains the flexibility to support multiple prediction modes while avoiding unnecessary bit overhead, thus improving coding efficiency without sacrificing mode selection capability
3Measurement precision
If chroma fusion merge mode is enabled for all blocks, then prediction quality is improved, but bit overhead increases
Solution Approach 1:
The patent applies local quality by allowing different encoding behaviors for different blocks based on their specific characteristics. Each block is evaluated to determine whether chroma fusion merge mode is appropriate, and the first syntax flag is only encoded when the mode is actually used in that specific block, thus optimizing the balance between prediction quality and bit overhead locally for each block
Data Source
Figure 1~2A
Figure 2B~3
Figure 4~5
AI summary
A coding method, a bitstream, an encoder, a decoder, and a storage medium are disclosed in embodiments of the disclosure. The method includes the following. Mode enable information of a current block is determined. If the mode enable information indicates that a weighted chroma fusion mode is used for the current block and a chroma fusion merge mode is enabled for the current block, a bitstream is decoded to determine a value of first syntax flag information. If the first syntax flag information indicates that the chroma fusion merge mode is used for the current block, the bitstream is decoded to determine an index value of the current block. A parameter candidate list of the current block is constructed, and a model parameter of the current block is determined according to the parameter candidate list and the index value, where the model parameter is used for determining a first prediction value of the current block based on a cross-component prediction mode. As such, bit overhead can be reduced, and thus the coding efficiency can be improved.