Adaptive Chroma Scaling in Video Decoding for Local Quantization

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Solution Overview

Problem

Existing video coding standards, such as ITU-T H.265 and JEM, face inefficiencies in adapting to variations in local characteristics of video data, particularly in determining quantization parameters for luma and chroma components, leading to suboptimal coding performance when dealing with diverse brightness, dynamic range, and color gamut in video frames.

Innovation Solution

Adaptive component scaling techniques are employed to independently determine and scale quantization parameters for luma and chroma components based on local characteristics, allowing for more precise adjustment of quantization levels to optimize video coding performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If existing video coding standards (ITU-T H.265, JEM) use unified quantization parameters for luma and chroma components, then device complexity is reduced, but coding performance deteriorates when dealing with diverse brightness, dynamic range, and color gamut characteristics

Engineering Contradiction:
Improvecoding performanceVSAvoidcomplexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent segments the quantization parameter determination process into separate independent paths for luma and chroma components. Different quantization parameters (QPY, QPCb, QPCr) are determined independently based on their respective component characteristics, allowing optimized coding performance for each component type while maintaining manageable system complexity through modular processing.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent applies local quality by determining quantization parameters specifically tailored to each color component's local characteristics. The scaling parameters and offset values are adjusted independently for luma and chroma components based on their specific brightness, dynamic range, and color gamut properties, enabling precise adaptation to local video data characteristics.

Inventive Principle:
Principle #3Local quality

2Productivity

If adaptive component scaling is implemented to independently determine quantization parameters for luma and chroma components, then coding efficiency is improved, but computational complexity increases

Engineering Contradiction:
Improvecoding efficiencyVSAvoidcomputational complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The patent implements dynamic adaptive component scaling where quantization parameters are flexibly adjusted based on local video data characteristics. The scaling parameters and offset values are dynamically determined for each coding unit, allowing the system to adapt to varying brightness, dynamic range, and color gamut conditions while maintaining coding efficiency through context-based parameter selection.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes multiple parameters including scaling parameters (scaleY, scaleCb, scaleCr), offset values (offsetCb, offsetCr), and quantization parameters (QPY, QPCb, QPCr) to achieve optimal coding efficiency. These parameter changes are applied adaptively based on component type and local video characteristics, enabling precise control over quantization behavior for different color components.

Inventive Principle:
Principle #35Parameter changes

3Manufacturing precision

If separate quantization parameters are determined for luma and chroma components based on local characteristics, then compression quality is improved, but processing time increases

Engineering Contradiction:
Improvecompression qualityVSAvoidprocessing time
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent performs preliminary determination of scaling parameters and offset values before the actual quantization process. By pre-calculating these parameters based on component type and local characteristics, the system reduces processing time during the main encoding/decoding operation while maintaining high compression quality through adaptive parameter selection.

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The system uses self-service by determining quantization parameters automatically based on inherent video data characteristics without requiring manual intervention. The adaptive component scaling mechanism autonomously selects appropriate parameters for luma and chroma components based on their local properties, improving compression quality while minimizing processing overhead through automated parameter derivation.

Inventive Principle:
Principle #25Self-service

Data Source

PatentEP3488610B1Device and method for decoding video data using adaptive component scaling
Publication Date: 2025.11.26 FG INNOVATION CO LTD
  • EP3488610B1 patent drawingFigure 1
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AI summary

A method of encoding and decoding video data is described. According to an aspect of an invention, luma and chroma components may have separate quadtree plus binary tree (QTBT) structures and a scaling parameter for a chroma coding block is determined based on one or more properties of a luma component.