Halftone Processing System for Moiré Pattern Elimination
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
When printed material is digitally scanned and then printed again, the halftoning used in the original printing and the output process can generate interference patterns (Moiré patterns) that significantly degrade the quality of the reproduced image.
Innovation Solution
A programmable halftone processing system that includes a segmentation module to classify image areas into halftone, edge, and background regions, and an output processing module that applies filtering to smooth halftone regions and enhance edges, using low-pass and high-pass filters to reduce or eliminate Moiré patterns while maintaining sharpness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If halftoning is applied in both original printing and output printing, then the original image can be reproduced, but Moiré patterns are generated that degrade image quality
Solution Approach 1:
The patent extracts and removes the halftone pattern from the scanned image through detection and filtering operations. The system identifies halftone regions and applies dehalftoning algorithms to eliminate the periodic structure that causes Moiré patterns, while preserving the underlying image content.
Solution Approach 2:
The patent changes the frequency domain parameters of the image by applying filters that target specific frequency ranges associated with halftone patterns. By modifying the frequency spectrum and reconstructing the image, the system eliminates Moiré patterns while maintaining image fidelity.
2Object-affected harmful factors
If filtering is applied to smooth halftone regions, then Moiré patterns are reduced, but edge sharpness may be degraded
Solution Approach 1:
The patent applies different processing characteristics to different regions of the image. Halftone regions are smoothed using low-pass filtering to reduce Moiré patterns, while edge regions are preserved or enhanced using edge detection and selective sharpening operations. This local differentiation allows simultaneous reduction of Moiré patterns and maintenance of edge sharpness.
Solution Approach 2:
The patent segments the image into distinct regions: halftone areas, edge areas, and background areas. By classifying pixels into these categories, the system can apply appropriate processing to each region - smoothing for halftone areas and preservation/enhancement for edge areas - thereby resolving the contradiction between Moiré reduction and edge sharpness.
3Device complexity
If a fixed halftone processing system is used, then the system is simple to implement, but it cannot adapt to different scanner and printer parameters
Solution Approach 1:
The patent implements a dynamic halftone processing system where parameters such as filter strength, frequency thresholds, and processing intensity are adjusted based on the specific scanner and printer characteristics. The system detects device parameters and automatically configures processing settings, enabling adaptability without requiring complex manual configuration.
Solution Approach 2:
The patent enables the system to automatically detect and adapt to different scanner and printer parameters without external intervention. The processing system self-configures by analyzing input image characteristics and device capabilities, selecting appropriate processing parameters and algorithms to optimize performance for each specific device combination.
Data Source
AI summary
A system for halftone processing is provided. The system includes a programmable halftone segmentation system having one or more programmable parameters to accommodate different input image parameters, such as different printer or scanner parameters, and configured to generate output control data as a function of image input data. A programmable output processor receives the output control data and the image input data and generates image output data that compensates for halftone regions in the image input data.