Image Processing Apparatus Lookup Table Multi-Pass Density
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image processing methods for multi-pass printing face challenges in suppressing density unevenness caused by printing position displacement between planes, leading to increased data processing load and time, especially when distributing multi-value density data for multiple printing scans or element groups.
Innovation Solution
An image processing apparatus and method that generates and quantizes multiple density data for the same color using a lookup table, allowing for efficient processing by reducing the need for additional circuits and minimizing processing time, while maintaining image quality by controlling dot overlap rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multi-pass printing is performed to reduce density unevenness caused by print element variation, then image uniformity is improved, but printing position displacement between planes causes new density fluctuations
Solution Approach 1:
The patent applies preliminary action by pre-calculating and storing optimal dot overlap rate settings in a lookup table before printing occurs. The image processing apparatus references this pre-prepared data during multi-pass printing to adjust dot overlap rates according to printing position, preventing density fluctuations caused by registration displacement without requiring real-time calculations.
2Reliability
If complex image processing is performed to compensate for printing position displacement, then density consistency is improved, but data processing load and time increase
Solution Approach 1:
The patent uses preliminary action by pre-calculating dot overlap rate compensation values for various printing conditions and storing them in a lookup table. During actual printing, the system simply references this pre-computed data rather than performing complex real-time calculations, thereby maintaining density consistency while minimizing processing load and time.
Solution Approach 2:
The patent applies copying by using a pre-generated lookup table that contains copied optimal settings for different printing scenarios. Instead of recalculating compensation parameters for each printing operation, the system copies and applies the appropriate pre-determined dot overlap rate from the lookup table based on current printing conditions.
3Reliability
If dot overlap rate is increased to compensate for printing displacement, then density consistency is improved, but image quality may deteriorate due to excessive dot accumulation
Solution Approach 1:
The patent applies local quality by adjusting the dot overlap rate according to the specific printing position and conditions. Rather than using a uniform dot overlap rate across the entire image, the system references the lookup table to apply locally optimized dot overlap rates that compensate for displacement only where needed, preventing excessive dot accumulation in areas where it would degrade image quality.
Data Source
AI summary
The present invention suppresses data processing load and processing time when generating density data for the same color that corresponds to a plurality of printing scans (or plurality of printing element groups) of a printing head and printing medium. In order to accomplish this, input image data is converted to a plurality of density data by referencing a three-dimensional lookup table that performs one-to-one correlation of input image data with a plurality of density data that corresponds to a plurality of relative movements (or plurality of printing element groups). By doing so, it is possible to perform a process of generating density data (CMYK) that corresponds to a plurality of relative movements (or plurality of printing element groups) from input image data at once, and thus it is possible to suppress an increase in data processing load and processing time.