Adaptive Entropic Decoder for Image Sign Coefficients
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current image and video compression methods, such as those using JPEG, MPEG, H.264, and HEVC, do not effectively adapt to the specific statistical properties of sign coefficients during encoding, leading to suboptimal compression performance due to the use of a single entropic encoder for all sequences, regardless of the sign prediction context.
Innovation Solution
A method that evaluates multiple value hypotheses for description elements in image blocks, calculates likelihood measurements, and uses the disparity in these measurements to determine adaptive parameters for an entropic decoder or encoder, allowing for context-specific and probability-based encoding/decoding, thereby improving compression efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If a single entropic encoder is used for all sign sequences, then the device complexity is reduced and ease of operation is improved, but the compression performance deteriorates due to inability to adapt to different statistical properties
Solution Approach 1:
The patent implements dynamic selection of entropic encoder contexts based on the statistical properties of sign sequences. The system evaluates multiple value hypotheses and selects the most appropriate encoder context dynamically, allowing the encoding process to adapt to different statistical characteristics of different blocks, thereby improving compression performance while maintaining operational simplicity
Solution Approach 2:
The patent changes the parameters of the entropic encoder (specifically the context parameters) based on the evaluated hypotheses of sign sequences. By adjusting the encoder parameters to match the statistical properties of the current block, the system achieves better compression ratios without requiring manual intervention or complex user configuration
2Productivity
If multiple entropic encoders are selected based on sign sequence statistics, then the compression performance is improved, but the device complexity increases
Solution Approach 1:
The patent segments the encoding process by dividing the image into blocks and evaluating each block's sign sequence statistics independently. This allows the system to use multiple encoder contexts selectively rather than maintaining all encoders active simultaneously, reducing the effective complexity while preserving the compression benefits of adaptation
Solution Approach 2:
The patent implements partial adaptation by evaluating multiple hypotheses but selecting only the most probable one for each block. This partial action approach provides sufficient adaptation to improve compression performance without requiring the full complexity of maintaining and switching between all possible encoder configurations
Data Source
AI summary
A method for decoding an encoded data stream representative of at least one image, which is divided into blocks. The decoding method includes, for a current block: evaluating a plurality of value hypotheses of at least one description element of the current block, by calculating a likelihood measurement per hypothesis; calculating a disparity in the likelihood measurements obtained; determining at least one parameter of a decoder based on the calculated disparity; decoding, using the determined decoder, complementary information for identifying at least one of the hypotheses; and identifying at least one of the hypotheses using the decoded complementary information and obtaining a value of the at least one description element for the current block, from the at least one identified hypothesis.