Adaptive Block Vector Resolution for Screen Content Video Coding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional video encoding methods for screen content, such as HEVC and VVC, fail to achieve high coding efficiency due to the lack of consideration for subpixel units in block vector expression, which is necessary for super high definition content.
Innovation Solution
Adaptive signaling of block vector spatial resolution and block vector difference sign to improve coding efficiency by allowing expression in subpixel units.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional encoding methods (HEVC, VVC) are used for screen content, then device complexity is reduced, but coding efficiency deteriorates due to lack of subpixel unit support
Solution Approach 1:
The patent applies dynamics by making the block vector precision adaptive rather than fixed. The encoder can dynamically select between 1-pel and 4-pel precision for block vectors based on the specific content characteristics, allowing the system to optimize coding efficiency for each block individually while managing overall complexity
Solution Approach 2:
The patent changes the precision parameter of block vectors from a fixed value to an adaptive parameter. By introducing different precision levels (1-pel and 4-pel) and selecting appropriate precision based on content type, the system improves coding efficiency for screen content while maintaining compatibility with conventional encoding frameworks
2Measurement precision
If block vector precision is increased to subpixel units, then measurement precision of block position is improved, but loss of information increases due to additional signaling requirements
Solution Approach 1:
The patent applies local quality by differentiating precision requirements across different spatial locations and content types. Instead of uniformly applying high precision to all blocks, the system uses 4-pel precision only where needed (screen content with complex patterns) and 1-pel precision elsewhere, optimizing the balance between precision and bitrate overhead
Solution Approach 2:
The patent implements partial action by selectively applying high-precision block vectors only to specific blocks that benefit from it, rather than to all blocks. This partial application of 4-pel precision reduces the overall signaling overhead while still capturing the benefits where complex patterns and edges require finer positioning accuracy
Data Source
AI summary
A method and an apparatus are disclosed for video coding using a block vector with an adaptive spatial resolution. The video coding method and the apparatus signal the spatial resolution of a block vector (BV) indicating the position of a reference block adaptively or signal the sign of a block vector difference adaptively in order to improve coding efficiency when intra block copy (IBC) is applied to a current block.