Adaptive Tone Mapping Curves for Scene-Specific Image Display

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Solution Overview

Problem

Display devices struggle to accurately reproduce the wide dynamic range of luminance values found in real-world scenes due to their limited display capabilities, leading to inadequate representation of both bright and dark regions.

Innovation Solution

An image processing method that adaptively determines interpolation points based on feature information and dynamic metadata, using modified spline curves to enhance tone mapping, allowing for flexible adjustment of luminance and contrast to improve the display of both bright and dark regions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a fixed tone mapping curve is used for all images, then the processing speed is fast and the device complexity is low, but the display effect for different scenes is poor and the adaptability is low

Engineering Contradiction:
Improveadaptability to different scenesVSAvoidcomplexity of tone mapping processing
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the tone mapping curve adjustable and adaptable to different scenes. Instead of using a fixed curve, the system dynamically selects and modifies tone mapping curves based on scene characteristics detected from feature information and dynamic metadata, allowing the processing to adapt to varying display requirements while maintaining reasonable complexity through algorithmic automation

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes parameters by modifying the tone mapping curve based on scene parameters extracted from feature information and dynamic metadata. The system adjusts curve characteristics such as luminance thresholds, contrast levels, and interpolation point positions according to the specific scene requirements, enabling optimized display effects for different content types without requiring completely different processing pipelines

Inventive Principle:
Principle #35Parameter changes

2Manufacturing precision

If the tone mapping curve is modified to improve display effect, then the display quality of bright and dark regions is improved, but the processing complexity and calculation amount increase

Engineering Contradiction:
Improveprecision of luminance reproductionVSAvoidcomplexity of curve modification processing
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies segmentation by dividing the tone mapping curve into multiple segments or sections that can be independently adjusted. The curve is segmented based on different luminance ranges (dark regions, mid-tones, bright regions), allowing precise control over each segment's characteristics while using standardized spline interpolation methods for each segment, thus improving luminance reproduction precision without excessively increasing overall processing complexity

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent uses spline curves as an intermediary mathematical tool to smoothly transition between different control points and segments of the tone mapping curve. This intermediary approach allows complex curve modifications to be achieved through controlled interpolation between key points, reducing the direct computational burden while maintaining high precision in luminance reproduction across the full dynamic range

Inventive Principle:
Principle #24Intermediary (Mediator)

3Manufacturing precision

If adaptive interpolation points are determined based on feature information, then the display effect for specific scenes is optimized, but the processing time and computational resources increase

Engineering Contradiction:
Improveprecision of tone mapping for specific scenesVSAvoidprocessing time for determining interpolation points
Core Design Contradiction:
Manufacturing precisionVSLoss of time

Solution Approach 1:

The patent applies preliminary action by pre-defining the structure and methodology for determining interpolation points based on feature information categories. The system establishes beforehand the types of feature information to analyze (luminance histograms, edge distributions, scene semantics) and the corresponding interpolation point placement strategies, allowing rapid processing during actual tone mapping while still achieving scene-optimized precision

Inventive Principle:
Principle #10Preliminary action

Solution Approach 2:

The patent applies local quality by placing different numbers and types of interpolation points at different locations on the tone mapping curve based on local scene characteristics. Areas of the curve corresponding to critical luminance ranges in the scene (such as shadow regions in low-light scenes or highlight regions in bright scenes) receive more detailed interpolation points, while other areas use fewer points, thus optimizing precision where needed while reducing overall processing time

Inventive Principle:
Principle #3Local quality

Data Source

PatentEP4036841B1Image processing method and apparatus
Publication Date: 2026.04.22 HUAWEI TECH CO LTD
  • EP4036841B1 patent drawingFigure 1
  • EP4036841B1 patent drawingFigure 2
  • EP4036841B1 patent drawingFigure 3

AI summary

This application provides an image processing method, including: adaptively determining at least one interpolation point based on feature information or dynamic metadata of a to-be-processed image, and determining the at least one interpolation point and a modified spline curve that passess through the at least one interpolation point, where the modified spline curve includes at least one of a linear spline curve or a cubic spline curve; and performing tone mapping on the to-be-processed image based on a modified tone mapping curve, where the modified tone mapping curve includes at least a part of an initial tone mapping curve and the modified spline curve. According to the method provided in this application, the tone mapping curve can be adaptively modified based on a scene requirement, so that images in various scenes can have a good display effect.