Mode-Specific Position-Dependent Intra Prediction Filtering for Video Coding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing video coding standards like VVC use the same positional weights for intra prediction modes regardless of block features, leading to suboptimal video compression efficiency.
Innovation Solution
Introduce adaptive position-dependent intra prediction sample filtering by using different weight arrays based on intra prediction modes, block sizes, and scales to optimize the PDPC process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If the same positional weights are used for all intra prediction modes, then the device complexity is reduced, but the video compression efficiency deteriorates
Solution Approach 1:
The patent applies different positional weight coefficients to different intra prediction modes (Planar, DC, Horizontal, Vertical, Angular modes). Each mode has its own optimized weight array that matches the spatial characteristics of that specific prediction mode, thereby improving compression efficiency without uniformly increasing complexity across all modes.
Solution Approach 2:
The patent changes the weight parameters based on the intra prediction mode being used. By selecting different weight arrays corresponding to different prediction modes, the system optimizes the PDPC filtering parameters to match the spatial distribution characteristics of each mode, resolving the contradiction between complexity and efficiency.
2Productivity
If different weight arrays are used for different intra prediction modes, then the video compression efficiency is improved, but the device complexity increases
Solution Approach 1:
The patent introduces dynamic selection of weight arrays based on the intra prediction mode. The system dynamically switches between different pre-defined weight arrays (e.g., wL[0..3] for Planar/DC modes, wL[4..7] for Horizontal/Vertical modes, wL[8..15] for Angular modes) rather than using a fixed weight set, allowing optimization for each mode while managing complexity through structured selection.
Solution Approach 2:
The patent segments the weight arrays into different groups corresponding to different prediction mode categories. By dividing the weight coefficients into mode-specific segments (Planar/DC segment, Horizontal/Vertical segment, Angular segment), the system manages complexity through organized structure while providing mode-specific optimization.
3Measurement precision
If position-dependent filtering is applied to all blocks, then the prediction accuracy is improved, but the processing complexity increases
Solution Approach 1:
The patent applies position-dependent filtering selectively rather than uniformly to all blocks. The PDPC filtering is applied based on specific conditions (certain intra prediction modes, block size constraints) rather than universally, providing accuracy improvement where needed while avoiding unnecessary processing complexity for blocks where simpler filtering suffices.
Data Source
AI summary
An apparatus directed to improvements of position-dependent intra prediction sample filtering process in video coding is provided. The apparatus receives a compressed bitstream and performs an intra prediction process based on an intra prediction mode for a current block to generate an intra predicted sample for a current sample in the current block. The apparatus determines a weight array based on the intra prediction mode for the current block, from a plurality of weight arrays, each of the plurality of weight arrays being associated with a respective one of a plurality of intra prediction modes, determines a weight from the determined weight array based on a position of the current sample, and generate a modified intra predicted sample for the current sample based on the determined weight and the intra predicted sample for the current sample.