Color Space Conversion Using Precomputed Lookup Tables

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Solution Overview

Problem

Current methods are inefficient for converting RGB values to RGBE values and vice versa due to the non-invertible nature of transformation matrices used in multi-primary color spaces, such as RGBE and RGBCW, which are non-square and cannot be inverted.

Innovation Solution

The use of a look-up table (LUT) generated with a numerical solver, based on a non-square transformation matrix, to approximate the inverse conversion from the XYZ color space to multi-primary color spaces like RGBE, enabling efficient conversions by determining optimal RGBE values for target XYZ values.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If a non-square transformation matrix is used to convert from multi-primary color space to XYZ color space, then the conversion capability is improved, but the matrix cannot be inverted for reverse conversion

Engineering Contradiction:

Improveconversion capabilityVSAvoidreverse conversion

Core Design Contradiction:

Adaptability or versatilityVSEase of operation

Solution Approach 1:

The patent pre-calculates and stores optimal RGBE values for multiple XYZ target values in a look-up table before actual conversion is needed. This preliminary action enables fast reverse conversion from XYZ to RGBE without requiring real-time inversion of the non-square matrix, thus resolving the contradiction between conversion capability and ease of reverse conversion.

Inventive Principle:

Principle #10Preliminary action

2Adaptability or versatility

If standard conversion methods are used from RGB to RGBE via XYZ color space, then conversion is possible, but the process is inefficient and time-consuming

Engineering Contradiction:

Improveconversion possibilityVSAvoidconversion efficiency

Core Design Contradiction:

Adaptability or versatilityVSProductivity

Solution Approach 1:

The patent pre-computes the conversion relationships and stores them in a look-up table, so that actual conversions can be performed by simple table lookups rather than through time-consuming matrix operations. This dramatically improves conversion efficiency while maintaining the ability to handle various color space conversions.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent creates a pre-computed lookup table that copies and stores the results of complex conversion calculations, allowing subsequent conversions to use these pre-stored values instead of recalculating them each time, thus improving productivity.

Inventive Principle:

Principle #26Copying

3Ease of operation

If direct inversion of non-square transformation matrix is attempted, then reverse conversion is pursued, but mathematical inversion is impossible

Engineering Contradiction:

Improvereverse conversionVSAvoidmathematical validity

Core Design Contradiction:

Ease of operationVSReliability

Solution Approach 1:

The patent introduces a look-up table as an intermediary between the non-square transformation matrix and the reverse conversion process. Instead of attempting to directly invert the matrix (which is mathematically impossible), the system uses the lookup table to map XYZ values to corresponding RGBE values, thus achieving reverse conversion without violating mathematical principles.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS9466260B2Conversion between color spaces

Publication Date: 2016.10.11 SAMSUNG DISPLAY CO LTD

AI summary

A computer-implemented method for converting a first color space to a second color space is provided. The method includes generating a look-up table (LUT) using a non-square transformation matrix and a numerical solver, wherein the LUT comprises a target value in the first color space and an optimal value in the second color space, and using the LUT to convert the first color space to the second color space.