Color Conversion Information for Dark Color Gamut Expansion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current image processing for printing lacks sufficient refinement in expanding the color gamut, particularly for dark colors, leading to limitations in ink usage and color saturation.
Innovation Solution
An image processing apparatus that converts RGB color space data to CMYK using a color conversion process with a specific configuration of color conversion information, where the output component values for black and magenta inks are adjusted to expand the color gamut by increasing the black ink component value closer to black and reducing the magenta ink component value, while maintaining constant values for cyan and yellow inks in intermediate ranges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If conventional color conversion information is used, then the color conversion process is simple, but the color gamut expansion is insufficient
Solution Approach 1:
The specific line on the color gamut outer envelope is divided into multiple ranges (first light range, first intermediate range, first dark range) based on distance from the black input color value. Different configuration rules are applied to each range, allowing precise control over color conversion behavior in different brightness regions while maintaining overall color gamut expansion.
Solution Approach 2:
Different output component value configuration rules are applied to different regions of the color gamut. In the first light range, the second output component value increases as input approaches black; in the first intermediate range, it remains constant; in the first dark range, it decreases. This local differentiation optimizes color representation across the entire gamut.
2Adaptability or versatility
If the second output component value is increased for all dark colors, then color saturation improves, but excessive ink usage occurs
Solution Approach 1:
The configuration of the second output component value is dynamically adjusted based on the input color value's position within different ranges. By changing the parameter behavior (increasing, holding constant, or decreasing) according to the specific range, the system achieves color saturation improvement without excessive ink consumption across all dark colors.
Solution Approach 2:
Different ink usage strategies are applied to different brightness regions. The second output component value is increased only in the first light range where it benefits saturation, held constant in the first intermediate range to maintain efficiency, and decreased in the first dark range to prevent excessive ink usage, creating locally optimized color reproduction.
3Manufacturing precision
If the first output component value is increased closer to black, then dark color representation improves, but overall ink consumption increases
Solution Approach 1:
The first output component value configuration is changed based on the input color value's proximity to black. Within the first light range, increasing the first output component value improves dark color representation. This parameter change is applied selectively rather than uniformly across all dark colors.
Solution Approach 2:
Different first output component value strategies are applied to different brightness regions. The value is increased in the first light range to improve dark color representation, held constant in the first intermediate range to maintain efficiency, and adjusted in the first dark range to optimize the balance between representation quality and ink consumption.
Data Source
AI summary
Color conversion information is used for carrying out a color conversion process to generate a converted image data. The color conversion information is configured as follows. Within a range from a predetermined first reference color value to a black input color value on a specific line, the closer to the black input color value a noticed input color value is, the larger a first output component value becomes. Within a first dark range, the closer to the black input color value the noticed input color value is, the smaller a second output component value becomes. Within a first light range, the closer to the black input color value the noticed input color value is, the larger the second output component value becomes. Within a first intermediate range, the second output component value is constant.