Image Processing Apparatus Blue Noise Threshold Matrices
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing image processing methods for printing color images using multiple color materials often result in noticeable graininess, particularly when using cyan, magenta, and yellow inks, as they can lead to conspicuous dot patterns and deteriorated image quality due to uneven dispersibility and dot power distribution.
Innovation Solution
An image processing apparatus and method that employs a color correlating process using threshold value matrices with blue noise characteristics, adjusting threshold values for each ink color to minimize graininess by setting threshold value matrices and reference colors such that the response value of each ink color's dot pattern is lower than the mixed color dot pattern, thereby maintaining image quality and reducing visual perception of graininess.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a dither method with a threshold value matrix is used for quantization, then processing load is reduced and dot dispersibility is improved, but graininess becomes conspicuous and image quality deteriorates
Solution Approach 1:
The patent applies different threshold value matrices with different blue noise characteristics to different color channels (cyan, magenta, yellow) individually. Each color channel receives a customized threshold matrix that optimizes dot dispersibility for that specific color, thereby reducing graininess while maintaining processing efficiency. This local optimization resolves the contradiction by improving image quality without significantly increasing processing load.
Solution Approach 2:
The patent modifies the threshold value parameters by using multiple threshold value matrices with different blue noise characteristics instead of a single fixed matrix. By changing the threshold parameters dynamically across different color channels and utilizing the statistical properties of blue noise, the method achieves better dot dispersibility and reduced graininess while maintaining the computational efficiency of the dither method.
2Manufacturing precision
If threshold values are adjusted for each ink color to minimize graininess, then image quality is improved, but device complexity increases
Solution Approach 1:
The patent pre-calculates and stores multiple threshold value matrices with different blue noise characteristics before the actual printing process. These pre-prepared matrices are then selected and applied to different color channels during quantization. This preliminary preparation reduces the computational complexity during real-time processing while maintaining the ability to optimize image quality through color-specific threshold adjustment.
Solution Approach 2:
The patent manages the complexity by systematically varying threshold parameters across different color channels using a set of pre-defined blue noise matrices. Instead of complex real-time calculations, the system uses parameter selection from pre-computed matrices, which simplifies the processing while achieving the goal of minimizing graininess through color-specific optimization.
Data Source
AI summary
An image processing apparatus sets a threshold value matrix for each of multiple color materials, and uses the set threshold value matrix to acquire a first threshold value. On the other hand, the image processing apparatus sets reference data on the basis of multivalued data of that color material. Then, the image processing apparatus calculates a second threshold value matrix by performing a predetermined process on the first threshold value on the basis of the reference data for that color material. Further, by comparing the second threshold value with the multivalued data, quantization data for printing a dot is generated. When doing this, the threshold value matrix and the reference data for that color material are set so as to make the graininess of a dot pattern of that color material lower than the graininess of a mixed color dot pattern obtained by mixing dot patterns of the respective multiple color materials.