Deblocking Filter Line Buffer Reduction via Sub-Boundary Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing video coding systems require significant line buffers for deblocking filters, which increase chip costs for on-chip memory implementation and power consumption for off-chip memory, necessitating a reduction in line buffer requirements.
Innovation Solution
The method reduces line buffers by using only reconstructed pixels from rows p0 and q0-q3 for luma and p0 and q0 for chroma components, applying vertical filtering only to these rows, and modifying the filtering decisions to include sub-sampled pixels from lines p1-p3 for improved filtering, thereby eliminating the need for additional line buffers beyond those used for intra prediction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If conventional deblocking filter is applied to all pixel rows, then filtering quality is improved, but line buffer requirements increase significantly
Solution Approach 1:
The patent segments the boundary between two blocks into multiple sub-boundaries, where each sub-boundary corresponds to a specific pixel row. Instead of applying filtering uniformly to all rows, the method processes each sub-boundary independently with its own filtering decision, allowing selective application of filtering only where needed based on local edge activity characteristics.
Solution Approach 2:
The patent implements local quality by making filtering decisions independent for each sub-boundary (pixel row) based on local edge activity measurements. Each row's filtering is determined by its specific characteristics rather than a global decision, allowing high filtering quality where edges exist while avoiding unnecessary filtering in smooth regions, thus reducing line buffer requirements.
2Reliability
If additional line buffers are allocated for deblocking filter, then filtering performance is improved, but chip cost and power consumption increase
Solution Approach 1:
The patent applies partial action by performing deblocking filtering only on specific sub-boundaries where edge activity indicates filtering is needed, rather than applying filtering to all pixel rows. This selective approach maintains filtering performance for regions requiring it while avoiding unnecessary processing and memory operations in regions where filtering would not improve quality, thereby reducing line buffer requirements and associated costs.
Solution Approach 2:
The patent changes the parameter of filtering application from a global uniform approach to a localized selective approach by introducing sub-boundary segmentation and independent filtering decisions for each sub-boundary. This parameter change allows the system to adapt filtering intensity and scope to local image characteristics, reducing overall memory requirements while maintaining performance where needed.
Data Source
Figure 1A
Figure 1B
Figure 2A
AI summary
A method and apparatus for deblocking of reconstructed video are disclosed. In one embodiment, the method divides a block boundary into two sub-boundaries and separates lines or column across the sub-boundaries into two groups. The deblocking filter decision for each group is determined based on the lines or columns in the respective group. In another embodiment, the method divides block edges of blocks in the LCUs into two edge groups, where the first edge group corresponds to horizontal block edges between two LCUs and the second edge group corresponds to remaining block edges not included in the first edge group. The number of lines processed by a vertical filter in the first edge group is less than the number of lines processed by a vertical filter in the second edge group. Accordingly, a system embodying the present invention has reduced storage requirement.