Intra Prediction Filter Switching for Wide-Angle Video Coding
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Solution Overview
Problem
Conventional video coding methods face complexity issues due to the high computational load of interpolation filters used for intra prediction, which hinders coding efficiency.
Innovation Solution
A method and device that selectively use either an interpolation filter or a reference filter based on the intra prediction mode index, reducing computational complexity by applying a reference filter when the mode index matches predefined indices corresponding to wide-angle modes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If an interpolation filter is used for intra prediction in conventional video coding, then prediction accuracy is improved, but computational complexity increases significantly
Solution Approach 1:
The patent changes the filter selection parameter based on the intra prediction mode index. When the mode index corresponds to a wide-angle mode, a reference filter is used instead of an interpolation filter, thereby reducing computational complexity while maintaining acceptable prediction accuracy for specific prediction scenarios
Solution Approach 2:
The patent segments the intra prediction modes into different categories (wide-angle modes vs. other modes) and applies different filtering strategies to each segment. This segmentation allows the system to use computationally lighter reference filters for wide-angle modes while preserving the accuracy benefits of interpolation filters for other modes
2Productivity
If the interpolation filter is used for all intra prediction modes, then coding efficiency is maintained, but the usage rate decreases due to computational burden
Solution Approach 1:
The patent introduces dynamic filter selection based on the intra prediction mode index. The filtering approach is not static but adapts dynamically to the specific prediction mode being used, selecting reference filters for wide-angle modes and interpolation filters for other modes, thereby optimizing the balance between coding efficiency and computational complexity
Data Source
AI summary
A method of decoding a bitstream is provided. The method determines a block unit of an image frame of the bitstream. The method determines an intra prediction mode index of the block unit, which corresponds to one of multiple wide-angle candidate modes, each having an angle parameter. The method determines reference samples neighboring the block unit and whether the determined intra prediction mode index is equal to one of predefined indices each corresponding to one of predefined wide-angle modes in the wide-angle candidate modes. The method generates filtered samples based on the determined reference samples. The filtered samples are generated by a reference filter when the determined intra prediction mode index is equal to the one of the predefined indices. The method reconstructs the determined block unit based on the generated filtered samples along a mode direction of the determined intra prediction mode index.