HDR Video Chrominance Adjustment for Tone-Mapping Consistency

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Solution Overview

Problem

Existing display devices struggle to accurately display High Dynamic Range (HDR) video signals due to luminance limitations, leading to visual differences in saturation and color temperature before and after tone-mapping processes.

Innovation Solution

A method and apparatus for adjusting saturation and chrominance components of HDR video signals based on luminance values and correction factors, considering the maximum values of multiple color components and using specific formulas to improve accuracy and consistency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If tone-mapping processing is performed on HDR video signals for display on devices with limited luminance capability, then the HDR signal can be displayed on current devices, but visual differences in saturation and color temperature occur before and after processing

Engineering Contradiction:
Improvecompatibility with display devicesVSAvoidvisual consistency
Core Design Contradiction:
Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by dynamically adjusting saturation adjustment factors based on luminance values and correction strength parameters. The system modifies saturation parameters selectively across different luminance ranges, using correction strength parameters to control the degree of saturation adjustment, thereby maintaining visual consistency while enabling display compatibility

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent implements local quality by applying different saturation adjustment factors to different color components (R, G, B) and different luminance ranges. The system calculates separate correction strength parameters for each color component and applies localized saturation adjustments rather than uniform processing, preserving visual consistency in specific regions while maintaining overall display adaptability

Inventive Principle:
Principle #3Local quality

2Manufacturing precision

If saturation adjustment is performed on color signals, then visual consistency is improved, but the complexity of signal processing increases

Engineering Contradiction:
Improvevisual consistencyVSAvoidsignal processing complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the saturation adjustment process into separate stages: first adjusting saturation for different color components (R, G, B) independently, then applying luminance-based corrections. The system segments the correction strength parameters into multiple levels based on luminance ranges, reducing processing complexity through structured decomposition

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent implements preliminary action by pre-calculating correction strength parameters and saturation adjustment factors before the main signal processing. The system prepares lookup tables and pre-computed correction values that can be applied during video processing, reducing real-time computational complexity while maintaining visual consistency

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP4037311B1Video signal processing method and apparatus
Publication Date: 2025.11.05 HUAWEI TECH CO LTD
  • EP4037311B1 patent drawingFigure 1-a~1-b
  • EP4037311B1 patent drawingFigure 2-a~2-b
  • EP4037311B1 patent drawingFigure 3-a~3-b

AI summary

A chrominance adjustment method and apparatus, and a storage medium are provided. The method includes: determining a color adjustment coefficient of a chrominance component of a color signal based on a reference display device maximum luminance value (RML) and/or a source maximum luminance value (SML); and adjusting the chrominance component of the color signal based on the color adjustment coefficient.