Color Conversion Processor for Natural Skin Tone Reproduction
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing color conversion methods fail to produce natural color representation of skin and lip tones in images taken under inadequate shooting environments, resulting in unnatural coloration such as skin appearing red or lips looking like they have excessive lipstick, due to insufficient consideration of varying conditions in the L*a*b* color space.
Innovation Solution
A color conversion system and method that implement distinct color conversion processes for image data in the L*a*b* color space, using a color conversion processor to differentiate between data positions within a constant hue line at a 45-degree angle and those outside this region, with the processor applying specific color conversion processes to move data points closer to the constant hue line in the yellow direction to achieve more natural color representation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If perceptive color conversion is applied to image data taken under inadequate shooting environment, then color coordinates are compressed within device reproduction range, but flesh color regions remain with retained hues resulting in unnatural coloration (skin tinged with red, lips with excessive lipstick)
Solution Approach 1:
The patent applies different color conversion strategies to different regions of the color space. Specifically, it identifies flesh color regions (skin and lip tones) and applies a specialized conversion process that moves color coordinates toward a constant hue line at 45 degrees, while other regions use conventional perceptive color conversion. This regional differentiation resolves the contradiction by ensuring natural color representation for flesh tones while maintaining overall color accuracy.
2Measurement precision
If perceptive color conversion is applied to all image data, then general color accuracy is maintained, but flesh color regions under inadequate shooting conditions produce unnatural results with retained saturation
Solution Approach 1:
The patent segments the color space into distinct regions: flesh color regions (skin and lip tones) and non-flesh regions. By identifying data positions within specific angular ranges on the a*b* plane (0-90 degrees relative to a* axis), it applies specialized processing only to flesh color regions while maintaining conventional processing for other areas. This segmentation eliminates unnatural coloration in flesh regions without compromising overall color accuracy.
3Adaptability or versatility
If color conversion compresses all data positions within device gamut, then device representation range is achieved, but flesh color naturalness is compromised due to retained hues in inadequate shooting conditions
Solution Approach 1:
The patent implements location-specific color conversion by detecting the position of color coordinates on the a*b* plane and applying different conversion rules based on location. For flesh color regions (within 0-90 degrees angular range), it applies a conversion that prioritizes naturalness by moving toward the 45-degree constant hue line. For other regions, it applies standard gamut compression. This ensures device compatibility while preserving flesh color naturalness.
Data Source
AI summary
For color conversion of image data in a L*a*b* color space, a color conversion system includes a color conversion processor to implement a first color conversion for color conversion of data positions of an image data in a reference-color representing first region covering a constant hue line at a prescribed hue angle on an a*b* plane, and a second color conversion for color conversion of data positions of the image data in a second region set outside the first region within an angular range smaller in hue angle than the prescribed hue angle on the a*b* plane, the prescribed hue angle being set up in an angular region of 0 degree or more and 90 degree or less relative to an a* axis, the color conversion processor being adapted to implement mutually different color conversion processes for the first color conversion and the second color conversion.