Image Processing Apparatus Nozzle Failure Compensation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Inkjet printing systems face issues with streak unevenness due to clogged nozzles, leading to unnatural density variations in printed images, as existing complementation techniques fail to effectively address nozzle failures.
Innovation Solution
An image processing apparatus and method that determines priority levels for dot arrangement based on pixel values and threshold values, rearranging dots to compensate for non-ejectable nozzles by preferentially placing dots in high-priority positions within the same target area, thereby maintaining image reproducibility and reducing density unevenness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a simple rule is applied in which a dot is complemented by alternately selecting pixels adjacent to a pixel expected to be formed by a non-ejectable nozzle from left and right, then the non-ejectable nozzle can be complemented, but unnatural density unevenness occurs locally
Solution Approach 1:
The patent applies local quality by determining priority levels for different pixel positions based on their specific characteristics and the non-ejectable nozzle position. Instead of uniformly selecting adjacent pixels from left and right, the system evaluates each pixel's priority level considering its distance from the non-ejectable nozzle, its position in the image, and the dot arrangement pattern. This localized evaluation ensures that complementation is performed with higher precision and fewer unnatural density variations.
Solution Approach 2:
The patent changes parameters by introducing priority level determination as a new parameter for pixel selection. The priority level is calculated based on multiple factors including the distance from the non-ejectable nozzle, the pixel position, and the dot arrangement pattern. By using this priority level parameter, the system can selectively choose which adjacent pixels to use for complementation, thereby achieving more natural density distribution compared to the simple alternating selection method.
2Manufacturing precision
If dots are rearranged to compensate for non-ejectable nozzles, then image reproducibility is improved, but the complexity of the processing increases
Solution Approach 1:
The patent applies preliminary action by pre-determining the priority levels for all pixels before actual dot arrangement. The priority levels are calculated based on the non-ejectable nozzle position, pixel positions, and dot arrangement patterns in advance. This preliminary determination simplifies the subsequent dot arrangement process, as the system only needs to follow the pre-established priority levels rather than performing complex real-time calculations during image formation.
Solution Approach 2:
The patent uses copying by creating a priority level map that mirrors the spatial relationships in the original image. The priority level determination process generates a complementary data structure that preserves the spatial information needed for dot arrangement while adding the priority evaluation layer. This copying approach allows the system to maintain image reproducibility without requiring complex real-time processing during actual printing.
Data Source
Figure 1
Figure 2
Figure 3
AI summary
The image processing apparatus of the present invention comprises: an acquisition unit (201) configured to acquire a pixel value group consisting of pixel values of a plurality of pixels included in a predetermined target area in image data; an acquisition unit (203) configured to acquire a threshold value group consisting of a plurality of threshold values corresponding to the plurality of pixels; a calculation unit (202) configured to calculate a target number of dots indicating a number of dots to be arranged within the target area; an acquisition unit (206) configured to acquire a pixel position at which a dot is expected to be formed by a non-ejectable nozzle in the image data as a non-ejectable nozzle position; and determination unit (205) configured to determine arrangement of dots in the target area based on a priority level determined based on the pixel value group and the threshold value group, the target number of dots, and the non-ejectable nozzle position.