Image Decoding Quantization Correction for Non-Negative QP
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In Versatile Video Coding (Draft 7), JVET-N 1001, the decoded quantization parameter can have negative values, which is undesirable.
Innovation Solution
An image decoding device and method that corrects the decoded quantization parameter based on whether adaptive color transform is applied to a target block, ensuring the quantization parameter is always 0 or more, using a quantization parameter deriving unit to set the larger of the corrected value and a predetermined value of 0 or more.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the decoded quantization parameter is used directly from Versatile Video Coding (Draft 7), then the decoding process follows the standard specification, but the quantization parameter value may become negative which is undesirable
Solution Approach 1:
The patent applies preliminary action by performing correction processing on the decoded quantization parameter before it is used in subsequent decoding operations. The quantization parameter deriving unit corrects the value based on whether adaptive color transform is applied, ensuring the parameter is valid (non-negative) before being used in inverse quantization processes. This prevents the harmful effect of negative values while maintaining decoding efficiency.
2Reliability
If correction processing is applied to ensure non-negative quantization parameter values, then the reliability of the quantization parameter is improved, but additional processing steps are required
Solution Approach 1:
The patent applies local quality by making the correction processing conditional rather than universal. The quantization parameter deriving unit checks whether adaptive color transform is applied to the current block and only performs correction when needed. This selective approach ensures reliability where required (when adaptive color transform is applied) while avoiding unnecessary processing elsewhere, thus resolving the contradiction between reliability and complexity.
Data Source
AI summary
An image decoding device includes a quantization parameter deriving unit configured to correct a value of a decoded quantization parameter of a target block depending on whether or not adaptive color transform has been applied to the target block, and then set, as the quantization parameter of the target block, the larger of the corrected value of the quantization parameter and a predetermined value of “0” or more.