Entropy Coding Group Formation in Display Interface Compression
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing display interface compression standards, such as VESA Display Compression-Mobile (VDC-M), face challenges in achieving high compression ratios while maintaining visually lossless quality, particularly in mobile devices, due to increased complexity and suboptimal entropy coding methods.
Innovation Solution
The implementation of a prefix coding method in an entropy coder that forms entropy coding groups using bit-based representations like two's complement and sign-magnitude, with separate prefix codebooks for each representation, to improve decoding throughput and compression efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a single prefix codebook is used for all bit-based representations, then the device complexity is reduced, but the compression efficiency and decoding throughput are suboptimal
Solution Approach 1:
The patent segments the single prefix codebook into multiple separate prefix codebooks, each optimized for a specific bit-based representation (e.g., one for two's complement, another for sign-magnitude). This segmentation allows the entropy coder to select the most appropriate codebook for each representation type, thereby improving compression efficiency and decoding throughput without requiring a single overly complex universal codebook.
Solution Approach 2:
The patent applies local quality by creating specialized prefix codebooks tailored to specific bit-based representations. Each codebook is optimized for its designated representation type, providing locally optimal compression performance for each representation rather than using a generic codebook that compromises overall efficiency.
2Loss of information
If multiple separate prefix codebooks are used for different bit-based representations, then compression efficiency is improved, but the device complexity increases
Solution Approach 1:
The patent implements preliminary action by pre-computing and storing multiple optimized prefix codebooks for different bit-based representations during system initialization or manufacturing. This allows the entropy coder to directly select and use the appropriate pre-prepared codebook without performing complex real-time optimization, thereby achieving high compression efficiency while limiting runtime computational complexity.
3Device complexity
If the entropy coding method is simplified, then the device complexity is reduced, but the compression ratio deteriorates
Solution Approach 1:
The patent applies parameter changes by modifying the prefix codebook selection parameter based on the bit-based representation being used. Instead of using a fixed or simplified single codebook, the system dynamically selects among multiple codebooks by changing the codebook selection parameter according to the representation type, thereby achieving better compression ratios without significantly increasing overall system complexity.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
A system and method of forming entropy coding groups in an entropy encoder includes providing multiple prefix codebooks, each prefix codebook being associated with a bit-based representation; receiving a block of sample values as a current block of sample values; forming multiple entropy coding groups; converting the sample values in each entropy coding group to a selected bit-based representation; determining the bit-based representation used for each respective entropy coding group; selecting a first or second prefix codebook for a respective entropy coding group in response to the determining; applying the selected prefix codebook to encode a prefix value of the respective entropy coding group; forming the bit-representation of the entropy coding groups, where the bit-representation of each entropy coding group includes a prefix encoded using the selected prefix codebook and one or more sample values; and providing the bit-representation of the entropy coding groups as an output.