Inkjet Image Processing for Sharp Contour Printing
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Solution Overview
Problem
Existing image processing methods for inkjet printers fail to maintain sharp contours and desired printing quality due to bleed-through issues, where lightening the ink density can lead to outlined contours or weeded-out dots, especially when printing characters or ruled lines.
Innovation Solution
An image processing method that discriminates between edge and inner pixel areas in a printing image, adjusting their densities based on a predetermined threshold value to prevent bleed-through while maintaining sharp contours, by setting the edge pixel area density differently from the inner pixel area density when the correction density is above or below the threshold.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If the density of ink is lightened to suppress bleed-through, then ink bleed-through is reduced, but the contour of the character becomes outlined and readability deteriorates
Solution Approach 1:
The patent applies different ink densities to different regions of the character: the inner pixel area (filling region) uses lightened ink density to suppress bleed-through, while the edge pixel area (contour region) maintains normal or darkened ink density to preserve sharp contours. This local differentiation resolves the contradiction by allowing each region to have the density appropriate for its function.
Solution Approach 2:
The character image is segmented into two distinct pixel areas: inner pixel areas and edge pixel areas. This segmentation allows independent control of ink density for each region, enabling the inner area to be lightened for bleed-through prevention while the edge area maintains sharpness, thus resolving the technical contradiction.
2Object-affected harmful factors
If the density of ink forming a contour line is lightened to suppress bleed-through, then ink bleed-through is reduced, but the gray scale value is lowered and dots are weeded out, preventing sharp contour printing
Solution Approach 1:
The patent applies different ink density treatments to different regions: edge pixels forming contours maintain normal or enhanced density to ensure sharp, complete contour lines, while inner pixels use lightened density to prevent bleed-through. This local quality differentiation prevents both contour bleed-through and dot weeding.
Solution Approach 2:
The image is segmented into edge pixel areas and inner pixel areas, allowing the contour-forming edge pixels to maintain sufficient ink density for sharp printing while the inner pixels are lightened. This segmentation prevents the harmful effect of lightening on contour sharpness.
3Object-affected harmful factors
If the density of a character is lightened to suppress bleed-through, then ink bleed-through is reduced, but the character is outlined with a darkened contour and the desired printing image cannot be obtained
Solution Approach 1:
The patent applies selective density adjustment: the inner pixel area uses lightened ink density to suppress bleed-through, while the edge pixel area uses normal or darkened density to maintain proper contour appearance. This prevents the unwanted outlined effect while still achieving bleed-through suppression.
Solution Approach 2:
By segmenting the character into inner and edge pixel areas, the patent enables differential density control that prevents the overall lightening from creating unwanted outlined contours, thereby maintaining desired printing image quality while suppressing bleed-through.
Data Source
AI summary
An image processing method includes a correction density setting step, a pixel area discrimination step for extracting, based on image data, an edge pixel area including an edge pixel constituting a contour of a printing image, and discriminating an inner pixel area surrounded by the edge pixel area and the edge pixel area, a printing density setting step for setting a printing density of the inner pixel area as a correction density and a printing density of the edge pixel area as a printing density different from the correction density when the correction density is equal to or greater than a predetermined density threshold value, and setting the printing density of the inner pixel area and the printing density of the edge pixel area as the correction density when the correction density is less than the predetermined density threshold value, and a printing data generation step.