Inkjet Quantization Using Dot Influence Value
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional inkjet printing methods suffer from varying printing quality due to uneven ink dot concentration, leading to rough textures when attempting to print smooth surfaces like human skin, primarily caused by inadequate quantization processing.
Innovation Solution
The proposed solution involves an image processing unit that calculates a dot influence value based on a dot model, considering the overlap of adjacent ink dots and adjusting quantization processing to reflect this value, particularly in medium gradation areas to prevent pattern noise, while using error diffusion and dither methods to enhance printing quality.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional quantization processing is used, then the printing process is simple and fast, but concentration unevenness occurs due to overlapping ink dots
Solution Approach 1:
The patent calculates the dot influence value in advance during the quantization processing stage, before actual printing occurs. This preliminary calculation predicts the overlapping effect of adjacent ink dots and adjusts the quantization thresholds accordingly, preventing concentration unevenness from the outset without requiring post-printing corrections or slower processing speeds.
Solution Approach 2:
The patent introduces a new parameter called 'dot influence value' that quantifies the overlapping effect of adjacent ink dots. By changing the quantization processing parameters based on this new parameter, the system achieves both speed and precision - the dot influence value guides adjusted quantization thresholds that prevent concentration unevenness while maintaining efficient processing.
2Device complexity
If conventional quantization processing is used, then the processing method is simple, but concentration unevenness causes rough texture in smooth areas
Solution Approach 1:
The patent introduces the 'dot influence value' as an intermediary parameter between the input image data and the final quantization output. This intermediary calculates the expected dot overlap based on adjacent pixel information and uses it to adjust quantization thresholds, thereby eliminating rough textures in smooth areas without significantly complicating the overall processing architecture.
Solution Approach 2:
The patent implements a feedback mechanism where the quantization processing uses information about adjacent pixels (which will become adjacent ink dots) to adjust the current pixel's quantization threshold. This feedback from neighboring pixels prevents concentration unevenness and maintains surface smoothness in the output image.
3Manufacturing precision
If dot influence value is calculated for each pixel, then concentration unevenness is suppressed, but processing time increases
Solution Approach 1:
Instead of calculating dot influence values for all pixels independently (which would be excessive and time-consuming), the patent applies partial action by calculating dot influence values only for pixels where adjacent dots are likely to overlap. The system uses the dot model to predict overlapping conditions and focuses computational resources only on those critical pixels, achieving concentration uniformity without unnecessary processing time for all pixels.
Data Source
Figure 1A~1B
Figure 2A~2C
Figure 3A~3B
AI summary
A printing system 10 performs inkjet printing, the printing system including an image processing apparatus 12 which is an image processing unit that generates a generated image by image processing, and a printing apparatus 14 which is a printing unit that performs printing on a medium based on the generated image. The image processing apparatus 12 generates the generated image by performing quantization processing that performs quantization by comparing the pixel value of each pixel in the input image with a threshold, and in the quantization processing, calculates a dot influence value indicating to what extent a position corresponding to a selected pixel is covered by the ink dots formed at positions set on the medium in correspondence with the peripheral pixels peripheral to the selected pixel, performs an adjustment of reflecting the dot influence value on at least one of the pixel value of the selected pixel or the value of the threshold, and compares the pixel value and the threshold based on the values after adjustment.