Picture Coding with Adaptive VLC Tables for Non-Zero Coefficients
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional picture coding methods use a single VLC table for both intra and inter prediction coding, leading to inefficient coding due to varying picture quality, as they do not adaptively refer to optimal tables based on the number of coefficients in each block.
Innovation Solution
A picture coding method that calculates a predictive value for the number of coefficients in a block based on neighboring coded blocks, selects optimal VLC tables for variable length coding, and performs coding using these selected tables to improve efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single VLC table is used for both intra and inter prediction coding, then the device complexity is reduced, but the coding efficiency deteriorates due to varying picture quality
Solution Approach 1:
The patent divides the single VLC table into multiple separate VLC tables (first VLC table and second VLC table), each optimized for specific coding scenarios. This segmentation allows the system to select the appropriate table based on the number of non-zero coefficients, thereby improving coding efficiency without significantly increasing overall system complexity.
Solution Approach 2:
The patent introduces dynamic selection of VLC tables based on the number of non-zero coefficients in the current block. Instead of using a fixed single table, the system dynamically switches between different VLC tables according to the actual coding conditions, optimizing coding efficiency for varying picture qualities while maintaining manageable device complexity.
2Productivity
If multiple VLC tables are prepared and switched according to the number of non-zero coefficients, then the coding efficiency is improved, but the device complexity increases
Solution Approach 1:
The patent uses the number of non-zero coefficients as a key parameter to determine which VLC table to use. By changing the selection criterion based on this parameter, the system achieves adaptive coding efficiency improvement. The complexity increase is mitigated by using a simple threshold-based selection mechanism rather than complex decision logic.
3Measurement precision
If variable length coding is applied to the number of non-zero coefficients, then the coding precision is improved, but the device complexity increases due to additional coding requirements
Solution Approach 1:
The patent performs variable length coding on the number of non-zero coefficients before proceeding to the actual coefficient coding. This preliminary action provides accurate information about the block's characteristics, enabling more precise subsequent coding. The increased complexity is offset by the efficiency gains from this preliminary precision measurement.
Data Source
AI summary
The method includes the following units: a coefficient number detecting unit (109) for detecting the number of coefficients which has a value other than 0 for each block according to the generated coefficient, a coefficient number storing unit (110) for storing the number of coefficients detected, a coefficient number coding unit (111) for selecting a table for variable length coding based on the numbers of coefficients in the coded blocks located on the periphery of a current block to be coded with reference to the selected table for variable length coding so as to perform variable length coding for the number of coefficients.