Multi-ink Vector Halftoning for Extended Color Gamut
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Solution Overview
Problem
Current printer technologies using CMYK color models are limited in their color gamut, making it difficult to print certain colors, especially complementary colors like deep red, green, and blue, which are hard to reach and often require mutual exclusivity, restricting the extension of the 4-color gamut and limiting the production of neutral hues.
Innovation Solution
Implementing multi-level drop size vector halftoning that converts CMYK contone images to multi-bit outputs, where complementary colors are treated as different drop sizes of a single color, allowing for binary vector halftoning and multi-level processing to determine ink amounts, enabling the simultaneous use of complementary colors without mutual exclusivity, thus extending the color gamut without requiring a hybrid CMYK-RGB system.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If additional color inks are added to extend gamut, then color gamut is improved, but device complexity increases
Solution Approach 1:
The patent merges complementary colors (e.g., red and cyan) into a single color channel by treating them as different drop sizes of the same ink. This combining approach allows the system to utilize additional color inks for gamut extension while reducing the effective number of separate color channels that need to be managed, thereby mitigating the increase in device complexity.
Solution Approach 2:
The patent makes a single color channel serve multiple functions by representing both a color and its complement within the same channel. The color value becomes a function of both the original color and its complement, allowing one channel to handle what would traditionally require separate channels, thus extending color gamut without proportionally increasing device complexity.
2Adaptability or versatility
If complementary colors are used simultaneously, then color reproduction is improved, but manufacturing precision deteriorates
Solution Approach 1:
The patent changes the parameter representation by making the color value a function of both the original color and its complement rather than treating them as independent variables. This parameter transformation allows complementary colors to be used simultaneously for gamut extension while maintaining control over ink deposition precision through the unified channel management.
3Manufacturing precision
If multi-bit output is used for vector halftoning, then manufacturing precision is improved, but device complexity increases
Solution Approach 1:
The patent combines multiple color channels into fewer channels by merging complementary colors. This reduction in the number of separate channels simplifies the halftoning process and reduces device complexity while still allowing multi-bit output to be used within each unified channel to maintain manufacturing precision for drop size control.
Data Source
AI summary
According to exemplary methods, a print job including an electronic document having a color image is received into a computerized device having a marking device including a print engine. A sheet of the print job is analyzed by the computerized device. In the analysis, a contone of the color image is converted to multi-bit output using multi-level vector halftoning. Pairs of complementary colors are selected, and substitute color channels for drop sizes are determined for each pair of complementary colors. Binary vector halftoning is applied using the substitute color channels for each pair of complementary colors. It is determined if ink is to be printed for the complementary colors. Multi-level processing is applied to determine an amount of ink for one color of each of the pairs of complementary colors. Pixels of the color image are rendered using the ink amount for the color of the pair of complementary colors.