Halftone Screen Threshold Layout for Moiré-Resistant Pattern Embedding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing halftone screens in printing technologies struggle to avoid moiré patterns and effectively embed patterns in printed outputs, particularly in three-dimensional printing, where voxel clusters can interfere with image quality.
Innovation Solution
A method to increase the number of grey levels in a greyscale image and distribute pixels or sub-pixels evenly across these levels, allowing for the creation of halftone screens that include intentional patterns, such as logos or watermarks, by converting greyscale images into threshold values using a computer-implemented process.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If traditional halftone screens are used for printing, then the printing process is simple, but moiré patterns appear and image quality deteriorates
Solution Approach 1:
The halftone screen is divided into multiple tiles, each containing a subset of pixels from the distributed pattern. This segmentation allows the overall pattern to be distributed across the entire printed image while maintaining local simplicity in each tile, thereby reducing moiré patterns without significantly complicating the printing process
Solution Approach 2:
The patent transitions from traditional uniform halftone screens to a distributed pattern approach where pixels are arranged according to their grey level values across multiple tiles. This dimensional reorganization of pixel distribution transforms the halftone rendering mechanism, improving image quality and reducing moiré effects while maintaining practical implementability
2Manufacturing precision
If pixels are evenly distributed across grey levels to create patterns, then image quality improves, but the complexity of generating halftone screens increases
Solution Approach 1:
The patent creates a master distributed pattern by sorting all pixels according to their grey level values and arranging them in a systematic sequence. This master pattern is then copied and tiled across the entire halftone screen, significantly reducing the computational complexity of generating large halftone screens while maintaining the precise pixel distribution required for high image quality and effective pattern embedding
Solution Approach 2:
The distributed pattern is pre-calculated and stored as a reusable template before actual halftoning operations. This preliminary creation of the pattern allows subsequent halftone screens to be generated efficiently by simply tiling the pre-computed pattern, reducing the complexity of real-time halftone screen generation while maintaining precise control over pixel distribution
Data Source
Figure 1
Figure 2A~2D
Figure 3
AI summary
In an example, a method includes, by one or more processors, receiving a greyscale image having a plurality of pixels, each pixel being associated with a grey level, and the greyscale image having a first number of grey levels. An order of the pixels may be determined based on the grey level. A second number of grey levels may be determined, wherein the second number of grey levels is greater than the first number, and an indication of a target number of pixels per grey level of the second number of grey levels may be further be determined. Taking the pixels in order, and based on the target number of pixels per grey level, a new grey level may be allocated to each pixel to provide the second number of grey levels. The new grey levels may be converted to a threshold of a threshold halftone screen.