Color Conversion Table Smoothing for Tone and Reproducibility

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Solution Overview

Problem

Existing color conversion techniques that smooth color tables to prevent tone jumps often compromise color reproducibility, particularly when converting RGB or Lab color spaces to YMCK, leading to deteriorated tone characteristics, especially for high saturation and low lightness colors.

Innovation Solution

An information processing apparatus that executes a first smoothing process on the black component of a color conversion table, calculates other color components using the smoothed black component, and updates the table to maintain color reproducibility while improving tone characteristics by adjusting weight coefficients for weighted averages.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Manufacturing precision

If a color conversion table is smoothed to prevent tone jumps, then tone characteristics are improved, but color reproducibility is deteriorated

Engineering Contradiction:

Improvetone characteristicsVSAvoidcolor reproducibility

Core Design Contradiction:

Manufacturing precisionVSMeasurement precision

Solution Approach 1:

The patent divides the color conversion table smoothing process into separate processing stages: first smoothing the black component (K) independently, then using the smoothed black component to calculate and smooth other color components (Y, M, C). This segmentation allows targeted smoothing of the black component to improve tone characteristics while controlling the smoothing of other components to maintain color reproducibility.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The patent applies different smoothing approaches to different color components. The black component undergoes full smoothing processing, while other color components use the smoothed black component as a reference for their calculation. This local differentiation optimizes tone characteristics for black-dominated regions while preserving color accuracy for other regions.

Inventive Principle:

Principle #3Local quality

2Adaptability or versatility

If grid points of color conversion table have large differences, then color conversion range is expanded, but tone characteristics are deteriorated

Engineering Contradiction:

Improvecolor conversion rangeVSAvoidtone characteristics

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent performs preliminary smoothing of the black component before using it to calculate other color components. This preliminary action ensures that the foundation (black component) is smooth, which prevents tone jumps in subsequent color calculations while maintaining the ability to handle a wide color conversion range.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The smoothed black component serves as an intermediary reference for calculating other color components. By using the smoothed black component as a mediator in the calculation process, the patent achieves smooth tone transitions while maintaining color conversion accuracy across a wide range.

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS11350016B2Information processing apparatus, image forming apparatus, and non-transitory computer readable medium

Publication Date: 2022.05.31 FUJIFILM BUSINESS INNOVATION CORP

AI summary

An information processing apparatus includes: a processor configured to execute a first smoothing process of smoothing a black component of a color conversion table, calculate other color components of the color conversion table using the black component for which the first smoothing process is executed, and execute a first update process of updating the color conversion table based on the black component for which the first smoothing process is executed and the calculated other color components.