Monochrome Image Processor Ink Density Correction
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Solution Overview
Problem
Inkjet printing of monochromatic images using pigment inks faces challenges with the bronzing phenomenon, where reflected light produces a complementary hue, and color rolling, where additional chromatic ink application can disrupt hue balance, making it difficult to produce high-quality monochrome images.
Innovation Solution
An image processing method and processor that generate multivalued density data for achromatic and chromatic inks, where the first chromatic ink corrects hue deviations in low to medium density regions and the second chromatic ink suppresses bronzing in high density regions, using a combination of cyan, magenta, and green inks to balance ink volumes and prevent color rolling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If yellow ink is applied to suppress bronzing phenomenon, then bronzing is reduced, but yellowish hue emerges over the entire image
Solution Approach 1:
The patent applies different chromatic inks to different density regions of the image. Specifically, it uses a first chromatic ink (e.g., cyan) for low to medium density regions and a second chromatic ink (e.g., magenta or yellow) for high density regions. This local differentiation allows suppression of bronzing in high density areas while preventing yellowish hue in low density areas, thus resolving the contradiction between reducing bronzing and maintaining hue accuracy.
Solution Approach 2:
The patent changes the parameter of chromatic ink type based on the density region. By switching between different chromatic inks (first chromatic ink for low-medium density, second chromatic ink for high density), the system dynamically adjusts the color correction strategy to match the local density characteristics, thereby suppressing both bronzing and unwanted hue shifts.
2Manufacturing precision
If additional chromatic ink is applied to reverse hue deviation, then hue deviation is corrected, but color rolling occurs due to disrupted hue balance
Solution Approach 1:
The patent applies chromatic inks locally to specific density regions rather than uniformly across the entire image. The first chromatic ink is applied to low to medium density regions where hue deviation is most noticeable, while the second chromatic ink is applied to high density regions where bronzing occurs. This localized approach corrects hue deviation without causing color rolling.
Solution Approach 2:
The patent uses partial action by applying chromatic inks only to specific density regions rather than the entire image. The first chromatic ink is applied partially to low to medium density regions, and the second chromatic ink is applied partially to high density regions. This selective application corrects hue issues without over-correcting and causing color rolling.
3Object-affected harmful factors
If chromatic ink volume is increased to suppress bronzing, then bronzing is reduced, but hue balance is disrupted causing color rolling
Solution Approach 1:
The patent applies different chromatic inks to different density regions, with the second chromatic ink (e.g., magenta or yellow) applied to high density regions to suppress bronzing, while the first chromatic ink (e.g., cyan) is applied to low to medium density regions to maintain hue balance. This spatial differentiation allows bronzing suppression without disrupting overall hue balance.
Solution Approach 2:
The patent changes the chromatic ink type parameter based on density region. By switching from the first chromatic ink to the second chromatic ink as density increases, the system optimizes both bronzing suppression and hue balance maintenance, avoiding color rolling that would result from uniformly increasing chromatic ink volume.
Data Source
AI summary
An image processor and an image processing method are provided which can suppress both a bronzing phenomenon and a color rolling in an inkjet printing apparatus and produce high-quality monochrome pictures. To that end, a monochrome image is processed by generating the multivalued density data for a chromatic ink having a hue component opposite that of the achromatic ink in a low to medium density region and, in a high density region, generating the multivalued density data for a chromatic ink having a reflection light with a hue component opposite that of a reflection light of the achromatic ink. With this arrangement, a high-quality monochrome image can be produced which has hardly noticeable hue deviations and bronzing phenomenon in the entire density grayscale or density range.