Raster Image Processing for Text Edge Sharpness and Quality Consistency
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current print systems face challenges in maintaining consistent print quality when handling documents with overlapping, transparent objects, as existing methods fail to accurately handle pixel attributes and transitions between different image processing methods for text and non-text objects.
Innovation Solution
The method involves determining the font size of text objects to switch between raster image processing methods, tagging text objects appropriately to prevent transitions, and setting thresholds for print quality, allowing for optimal processing of text objects as text or non-text based on font size and colorant density.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If text objects are processed using text-specific image processing methods to maintain sharp edges, then text quality is improved, but visible transitions occur when text objects overlap transparent objects
Solution Approach 1:
The patent applies different image processing methods to different regions based on local characteristics. Specifically, it determines whether each text object overlaps with transparent objects and applies text-specific processing only to non-overlapping regions, while using general image processing for overlapping regions. This local differentiation resolves the contradiction by maintaining sharp edges where appropriate while ensuring consistency where transparency effects occur.
Solution Approach 2:
The patent performs preliminary determination of text object characteristics and transparency overlap status before applying image processing methods. By pre-identifying which text objects are affected by transparency, the system can pre-plan the appropriate processing strategy, preventing visible transitions before they occur and maintaining both edge sharpness and quality consistency.
2Ease of operation
If general image processing methods are applied to all objects, then processing simplicity is maintained, but text objects lose their sharp edges and quality deteriorates
Solution Approach 1:
The system maintains processing simplicity by using a general image processing framework while introducing local quality enhancement only where needed. Text-specific processing is applied selectively to text objects that do not overlap transparent objects, preserving sharp edges without complicating the overall processing pipeline for all objects.
Solution Approach 2:
Instead of applying complex text-specific processing to all text objects, the patent applies it only partially to those that benefit most (non-overlapping text). This partial action approach maintains simplicity while achieving the necessary quality improvement for critical regions.
3Productivity
If font size threshold is used to determine processing method, then processing efficiency is improved, but small text objects may be incorrectly processed as non-text
Solution Approach 1:
The patent incorporates feedback mechanisms in the determination process by considering multiple characteristics (font size, colorant density, transparency overlap status) rather than relying solely on font size threshold. This multi-factor feedback approach improves classification accuracy while maintaining processing efficiency by quickly eliminating objects that clearly don't meet criteria.
Solution Approach 2:
The system uses multiple parameters (font size, colorant density, transparency status) instead of a single font size threshold to determine processing method. By changing from a single-parameter to multi-parameter decision framework, the patent improves classification accuracy while maintaining efficiency through systematic evaluation of each parameter.
Data Source
Figure 1~2
Figure 3
Figure 4
AI summary
A method is provided for converting print data to raster image data. The print data comprise objects with object attributes, whereas the raster image data comprise pixels with a colorant value, indicating an amount of colorant to be applied on a pixel position, and a pixel attribute for controlling a raster image processing step, which is applied in deriving a print signal from the raster image data, A value of a pixel attribute of a pixel within an object is selected in dependence of a value of an object attribute of said object, wherein a first value of a pixel attribute is selected for a pixel within an object having an object attribute with a value text object and an object attribute font size with a value higher than a predetermined threshold and a second value, different from the first value, of a pixel attribute is selected for a pixel within an object having an object attribute with a value text object and an object attribute font size with a value lower than said predetermined threshold. This method enhances the obtained print quality when the print data are received by a print system for printing, as unexpected transitions of print quality characteristices within a text element on a page of the printed output is avoided.