Wide-Angle Intra Prediction Mapping for Non-Square Block Decoding

The patent introduces an intermediary mapping mechanism that translates wide angle intra prediction modes into corresponding non-wide angle modes. This mediator layer enables the system to utilize wide angle modes for improved compression while maintaining compatibility with existing decoder architectures that may not directly support all prediction mode variants.

The patent modifies the intra prediction mode parameters by establishing a mapping between wide angle modes (spaced apart from vertical/horizontal modes by more than a threshold angle) and non-wide angle modes. This parameter transformation allows the system to adapt prediction modes to different block shapes (non-square blocks) while managing complexity through structured parameter relationships.

The patent makes the intra prediction mode selection dynamic by determining whether to use wide angle or non-wide angle modes based on the block shape. For non-square blocks, the system dynamically switches to wide angle modes when beneficial, while maintaining simpler decoding paths for square blocks, thus adapting the decoding process to the specific characteristics of each block.

The patent applies different prediction mode qualities to different block types. Non-square blocks receive the enhanced wide angle prediction modes for improved compression efficiency, while square blocks use the standard non-wide angle modes for simplicity. This localized optimization ensures that each block type receives the appropriate level of complexity based on its specific requirements.