Image Processing Method for Natural Color Changing via Luminance Adjustment

Solution Overview

Problem

Existing image processing methods for changing the color of specific areas in images, such as hair areas, result in unnatural and poor color changing effects due to direct replacement of initial colors with target colors.

Innovation Solution

A computer-implemented method that determines the initial luminance of target pixels based on their initial color values, and then adjusts these color values using color conversion information to match the illumination intensity, thereby enhancing the naturalness and effectiveness of the color changing effect.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If direct replacement of initial color with target color is used, then color changing operation is simple, but color changing effect is unnatural and poor

Engineering Contradiction:

Improvecolor changing operationVSAvoidcolor changing effect

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The patent applies parameter changes by introducing luminance as an additional parameter to control color transformation. Instead of directly replacing colors, the method converts initial color values to luminance values, applies luminance transformation rules to obtain target luminance, then converts back to color space. This parameter transformation approach (color → luminance → transformed luminance → color) resolves the contradiction by maintaining operational simplicity while achieving natural color changing effects through physics-based luminance relationships.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses luminance as an intermediary between initial color and target color. Rather than direct color replacement, the method introduces luminance transformation as a mediating step: initial color values are converted to luminance, luminance transformation rules are applied, and the result is converted back to color space. This intermediary approach ensures natural color transitions by preserving the relationship between color and illumination intensity, resolving the contradiction between simple operation and natural effect.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Speed

If initial color value is directly replaced by target color, then processing speed is fast, but color matching with illumination intensity is poor

Engineering Contradiction:

Improveprocessing speedVSAvoidcolor matching precision

Core Design Contradiction:

SpeedVSMeasurement precision

Solution Approach 1:

The patent applies parameter changes by transforming color values to luminance values and back, rather than directly replacing colors. This involves: converting initial color values to luminance values using color space transformation, applying luminance transformation rules to get target luminance, and converting target luminance back to color values. This parameter transformation maintains processing efficiency while achieving precise color matching with illumination intensity through physics-based relationships.

Inventive Principle:

Principle #35Parameter changes

3Manufacturing precision

If luminance transformation rule is applied, then color changing effect matches illumination intensity, but processing complexity increases

Engineering Contradiction:

Improvecolor changing effectVSAvoidprocessing complexity

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent applies parameter changes by transforming color values to luminance values and back, rather than directly replacing colors. This involves: converting initial color values to luminance values using color space transformation, applying luminance transformation rules to get target luminance, and converting target luminance back to color values. This parameter transformation maintains processing efficiency while achieving precise color matching with illumination intensity through physics-based relationships.

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The patent uses luminance as an intermediary between initial color and target color. Rather than direct color replacement, the method introduces luminance transformation as a mediating step: initial color values are converted to luminance, luminance transformation rules are applied, and the result is converted back to color space. This intermediary approach ensures natural color transitions by preserving the relationship between color and illumination intensity, resolving the contradiction between simple operation and natural effect.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentEP4207075B1Image processing method and apparatus, and computer device and storage medium

Publication Date: 2025.05.14 BEIJING SENSETIME TECH DEV CO LTD

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AI summary

An image processing method and apparatus, and a computer device and a storage medium. The method comprises: determining a target area corresponding to a target object in an image to be processed (S101); on the basis of initial color values of at least some target pixel points corresponding to the target area, determining initial brightnesses corresponding to the at least some target pixel points (S 102); and adjusting the initial color values of the at least some target pixel points on the basis of the initial brightnesses corresponding to the at least some target pixel points, and acquired preset color conversion information of the target area, so as to obtain a target image (S103).