Chromaticity Plane Color Mapping Method

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing color mapping techniques fail to accurately map source colors from one color gamut to another while ensuring all mapped colors remain within the target gamut, particularly when dealing with different luminance levels and gamut boundaries.

Innovation Solution

A method that maps source colors along a straight line in the chromaticity plane from a preserved gamut boundary color to a target gamut boundary color, using a plane of constant luminance and a mapping plane defined by the source, target, black, and white points, ensuring the mapping segment starts and ends within the target gamut boundaries.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If existing color mapping techniques are used to map source colors to target colors, then color transformation is achieved, but the mapped colors may fall outside the target gamut boundaries

Engineering Contradiction:
Improvecolor mapping accuracyVSAvoidgamut boundary compliance
Core Design Contradiction:
Manufacturing precisionVSReliability

Solution Approach 1:

The mapping process is segmented into distinct steps: identifying the mapping line through white point, determining the mapping plane through source and black points, finding the intersection with target gamut boundary, and establishing the mapping segment between preserved boundary color and target boundary color. This segmentation ensures each step contributes to keeping mapped colors within gamut boundaries.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from 2D chromaticity plane mapping to 3D color space mapping by introducing the mapping plane concept that includes the black point, white point, and source color. This dimensional extension ensures the mapping respects both chromaticity and luminance constraints, guaranteeing target gamut compliance.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Productivity

If a simple mapping approach is used, then the process is computationally efficient, but the mapping may not be reversible for restoring original colors

Engineering Contradiction:
Improvemapping computation speedVSAvoidcolor reversibility
Core Design Contradiction:
ProductivityVSLoss of information

Solution Approach 1:

The invention establishes a feedback mechanism by defining the mapping segment boundaries based on the target gamut boundary color intersection. This creates a reversible mapping where the target boundary color can serve as a reference point to reconstruct the original source color through inverse mapping operations.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The mapping preserves reversibility by maintaining the relationship between source colors, mapping line parameter (distance from white point), and target colors. The mapping segment definition ensures that parameter transformations remain invertible, allowing recovery of original colors from mapped colors.

Inventive Principle:
Principle #35Parameter changes

3Device complexity

If the mapping segment is not properly delimited, then the mapping process is simple, but mapped colors may not all remain within the target gamut

Engineering Contradiction:
Improvemapping process complexityVSAvoidtarget gamut compliance
Core Design Contradiction:
Device complexityVSManufacturing precision

Solution Approach 1:

The invention performs preliminary actions by pre-determining the mapping segment boundaries before actual color mapping. The preserved gamut boundary color and target gamut boundary color are identified in advance, ensuring that all intermediate mapped colors automatically fall within the target gamut without requiring complex runtime checks.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP3255875B1Method of mapping source colors of an image in a chromaticity plane
Publication Date: 2020.03.11 INTERDIGITAL VC HOLDINGS INC
  • EP3255875B1 patent drawingFigure 1
  • EP3255875B1 patent drawingFigure 2
  • EP3255875B1 patent drawingFigure 3

AI summary

Source colors are mapped within a mapping segment starting at a preserved gamut boundary color (Pc) and ending at a target gamut boundary color (IT-C) of the chromaticity plane, corresponding, in a linear 3D color space, to an intersection of the target color gamut (TCG) with a plane of constant luminance and with a mapping plane (MKO) comprising said source color (M), a black point (K) and a white point (O).