Pixel Insertion Control for Stable Dither Patterns in Electrophotographic Printing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In electrophotographic printing, sheet contraction or expansion during the fixing stage leads to size discrepancies between images on the front and back surfaces, causing instability in the dither pattern and affecting printing accuracy.
Innovation Solution
An image processing apparatus that determines pixel insertion or removal positions serially in a direction perpendicular to the variable magnification processing, restricting relative positions among pixels to be inserted or thinned off, ensuring stable dither patterns by controlling the distance from previous positions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If random pixel insertion or removal is executed to achieve variable magnification, then image quality is improved, but the dither pattern becomes broken and image stability deteriorates
Solution Approach 1:
The patent applies preliminary action by calculating and storing the positions of pixels to be inserted or removed before actually performing the insertion/removal operation. The position calculation unit determines which pixels will be affected by magnification changes, and this information is used to guide the subsequent pixel manipulation, preventing dither pattern disruption
Solution Approach 2:
The patent implements feedback by using the calculated pixel positions to adjust the magnification processing. The system continuously monitors which pixels fall within the magnification range and uses this information to determine subsequent insertion/removal positions, ensuring that the dither pattern remains intact while achieving the desired magnification effect
2Manufacturing precision
If sheet contraction or expansion is corrected by adjusting image information, then printing accuracy is improved, but processing complexity increases
Solution Approach 1:
The patent extracts only the necessary pixels for magnification adjustment rather than processing the entire image. The position calculation unit identifies specifically which pixels need to be inserted or removed based on the magnification range, allowing the system to focus processing efforts only on the affected regions and reduce overall processing complexity
Solution Approach 2:
The patent applies local quality by treating different regions of the image differently based on their magnification requirements. Pixels within the magnification range undergo insertion or removal processing, while pixels outside this range remain unchanged, allowing for efficient processing that maintains printing accuracy without unnecessary complexity
Data Source
AI summary
An image processing apparatus configured to execute variable magnification processing on an image includes a position determination unit configured to serially determine pixel insertion or removal positions in the image in a direction perpendicular to a direction of the variable magnification processing, and an insertion or removal processing unit configured to execute insertion or removal processing on pixels existing at the insertion or removal positions determined by the position determination unit. The position determination unit is configured to determine, within a range defined by a position distant from an immediately previously determined insertion or removal position by a first distance in the variable magnification processing direction and a position distant therefrom by a second distance in the variable magnification processing direction, a next insertion or removal position while referring to the immediately previously determined insertion or removal position.