Image Reading Apparatus Moire Pattern Reduction via Multi-Resolution Segmentation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Image reading apparatuses face challenges in producing high-quality image data due to the occurrence of moire patterns, particularly in color image reading systems where lighting frequency ratios and thinning control of lighting lines are not optimally managed.
Innovation Solution
The image reading apparatus includes a line sensor that reads the object at a first resolution and converts the image data into a second resolution lower than the first, with a shorter exposure time per line at the first resolution compared to the second resolution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If the image reader reads the reading object at a high first resolution, then the image quality is improved, but the exposure time per line becomes shorter which may reduce light capture and increase moire patterns
Solution Approach 1:
The patent segments the image reading process into two distinct resolution stages: a first reading at high resolution to capture detailed image information, and a second reading at low resolution to capture moire pattern information. This segmentation allows each reading to be optimized for its specific purpose, resolving the contradiction between capturing fine detail and avoiding moire artifacts.
Solution Approach 2:
The patent introduces a new dimension by performing readings at multiple resolution levels rather than a single resolution. By adding the resolution dimension as a variable parameter, the system can simultaneously obtain both high-resolution image data and low-resolution moire data, which are then combined to produce high-quality output free from moire patterns.
2Productivity
If the image reader reads at a lower second resolution directly, then the reading speed is faster, but the image quality and detail are lost
Solution Approach 1:
The patent divides the image acquisition process into two segmented readings: a fast low-resolution reading that captures moire pattern information, and a slower high-resolution reading that captures detailed image information. By segmenting the process, the system achieves both speed (through the fast low-res reading) and quality (through the high-res reading).
Solution Approach 2:
The patent performs a preliminary low-resolution reading first to capture moire pattern information before performing the high-resolution reading. This preliminary action allows the system to later remove moire patterns from the high-resolution image using the low-resolution data as a reference, thereby achieving both speed and quality.
3Manufacturing precision
If multiple readings are performed at different resolutions, then moire patterns are reduced, but the total reading time increases
Solution Approach 1:
The patent employs periodic action by performing two distinct readings with different characteristics (high-resolution and low-resolution) and then periodically combining them. This periodic multi-resolution approach achieves superior moire reduction compared to single-resolution readings, while the systematic combination process manages the time overhead efficiently.
Solution Approach 2:
The patent changes the resolution parameter between two readings: first reading at high resolution to capture image details, then changing to low resolution to capture moire patterns. By dynamically changing the resolution parameter, the system obtains complementary information from both readings that can be combined to reduce moire while maintaining quality, justifying the increased reading time.
Data Source
AI summary
An image reading apparatus includes an image reader that includes a line sensor to read a reading object line by line, and circuitry. The image reader reads the reading object at a first resolution and generates image data having the first resolution, and circuitry converts the image data having the first resolution into image data having a second resolution lower than the first resolution and outputs the image data having the second resolution. An exposure time per line is shorter when the reading object is read at the first resolution than when the reading object is read at the second resolution.