Wide-Angle Intra Prediction Mapping for Non-Square Coding Blocks
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Solution Overview
Problem
Existing video coding technologies face inefficiencies in intra prediction due to the limited number of directions and bit representation of less likely prediction modes, leading to suboptimal compression ratios and increased bit usage.
Innovation Solution
The proposed method involves remapping intra prediction modes for non-square block partitions using wide-angle modes based on aspect ratios, with a predefined number of mode replacements and angle parameters determined by a lookup table, allowing for more efficient encoding and decoding of video data.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional intra prediction modes with limited directions are used, then device complexity is reduced, but compression ratio deteriorates due to insufficient prediction accuracy
Solution Approach 1:
The patent applies dynamics by making the intra prediction mode selection adaptive rather than static. The encoder dynamically chooses between planar/DC modes and wide-angle modes based on the block's aspect ratio, allowing the prediction system to adapt to different block shapes and optimize compression performance accordingly.
Solution Approach 2:
The patent changes the parameter of prediction direction angles by introducing wide-angle modes with angles outside the traditional ±45° range. This parameter expansion allows better modeling of diagonal edges in non-square blocks, improving prediction accuracy and compression ratio without requiring a complete redesign of the intra prediction framework.
2Manufacturing precision
If more intra prediction modes with extended angles are added, then prediction accuracy improves, but bit usage increases for mode representation
Solution Approach 1:
The patent applies local quality by applying wide-angle prediction modes selectively only to non-square blocks where they provide benefit, rather than universally. Square blocks continue to use traditional planar/DC modes, avoiding unnecessary complexity and bit overhead for modes that would not improve prediction accuracy in that context.
3Productivity
If intra prediction is applied to non-square blocks with traditional modes, then coding simplicity is maintained, but coding efficiency deteriorates due to mismatched prediction directions
Solution Approach 1:
The patent applies preliminary action by pre-defining the mapping between traditional intra prediction modes and wide-angle modes based on aspect ratio thresholds. This lookup table approach allows the encoder to quickly determine the appropriate mode without complex real-time calculations, reducing computational overhead while improving coding efficiency.
Data Source
AI summary
Aspects of the disclosure provide methods and apparatuses for video encoding/decoding. In some examples, an apparatus for video decoding includes receiving circuitry and processing circuitry. The processing circuitry decodes prediction information of a current block from a coded video bitstream. In some embodiments, the processing circuitry determines a first sub-partition and a second sub-partition of the current block based on the decoded prediction information, and then reconstructs the first sub-partition and the second sub-partition of the current block based on at least a neighboring sample of the current block that is out of a neighboring area of at least one of the first sub-partition and the second sub-partition.