Video Coding Sign Prediction Contexts by Coefficient Position
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Solution Overview
Problem
Existing video coding techniques do not efficiently utilize the position of transform coefficients and coding modes to determine contexts for sign prediction syntax elements, leading to suboptimal coding efficiency.
Innovation Solution
Determine contexts for coding sign prediction syntax elements based on the position of transform coefficients and coding modes, such as inter or intra coding, to improve coding efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If existing video coding techniques use fixed contexts for sign prediction syntax elements, then device complexity is reduced, but coding efficiency deteriorates
Solution Approach 1:
The patent applies local quality by determining contexts based on local characteristics of transform coefficients, specifically their position within the block and the coding mode used. Different regions of the transform coefficient block receive different contexts tailored to their local statistical properties, improving coding efficiency without requiring globally complex adaptive models
Solution Approach 2:
The patent segments the context determination process into discrete categories based on transform coefficient position (e.g., different regions of the block) and coding mode (intra vs. inter). This segmentation allows the system to manage complexity by using a finite set of predefined contexts rather than requiring continuous adaptation, thus improving coding efficiency while controlling device complexity
2Loss of information
If video coding uses generic contexts for all transform coefficients, then ease of operation is improved, but loss of information increases
Solution Approach 1:
The patent changes the parameter used for context selection from generic block-level properties to specific transform coefficient position and coding mode. This parameter change enables more accurate sign prediction by capturing the statistical variations at different positions within the transform coefficient block, reducing information loss while maintaining operational simplicity through predefined context categories
Data Source
AI summary
A video coder may code a sign prediction syntax element that indicates whether a sign prediction hypothesis is correct for a transform coefficient. The video coder may code the sign prediction syntax element using a context-based coding process. The video coder may determine a context for coding the sign prediction syntax element based on a position of the transform coefficient in the block of video data. The context may be further based on a coding mode used to code the block.