Video Coding Deblocking With Chroma Quantization Groups

The patent applies different deblocking filter strengths to different video components (luma and chroma) based on their specific characteristics. The chroma component receives a reduced filter strength compared to luma, as chroma boundaries are less visually noticeable and stronger filtering would overly smooth important color information. This local differentiation optimizes compression performance while maintaining manageable processing complexity.

The patent segments the deblocking control into multiple hierarchical levels (picture level, slice level, tile level, brick level, subpicture level), allowing different chroma QP offsets to be applied at each level. This segmentation enables precise control over deblocking strength for different regions of the video, improving accuracy while the hierarchical structure allows for efficient implementation through inheritance and override mechanisms.

The patent implements position-dependent clipping by dynamically adjusting the clipping strength based on the spatial position of chroma blocks relative to boundaries. The clipping parameter varies according to whether the block is adjacent to a boundary and the specific boundary type (vertical, horizontal, diagonal), optimizing filter performance for chroma components while using computationally efficient clipping operations that add minimal processing time.