Reading Device Corner Shape Estimation for ID Card Scanning
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional reading devices struggle to accurately read the entire surface of ID cards with rounded corners, often missing data due to the device's limitations in reading the edge portions and including black areas in the image data where the white original holding sheet is not present, leading to incomplete image acquisition.
Innovation Solution
A reading device equipped with a controller that uses edge information from image data to estimate the round shape of the card's corners, allowing for accurate reading and correction of image data to exclude non-original areas, ensuring complete and accurate image capture of ID cards with rounded corners.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the original holding sheet is made smaller than the original placement area to prevent play, then the reliability of original restraint is improved, but the manufacturing precision of corner reading deteriorates because black areas appear in corners not covered by the holding sheet
Solution Approach 1:
The patent extracts and removes the black corner areas from the scanned image data through image processing. The controller identifies black regions in the four corners of the scanned original and deletes them from the image data, separating the useful image content from the harmful black areas caused by the holding sheet design.
Solution Approach 2:
The patent changes the parameter of the original holding sheet by making its corners rounded instead of sharp. This modification allows the holding sheet to better conform to rounded-corner originals (like ID cards) while maintaining restraint reliability, and the rounded corners reduce the formation of black areas in the scanned image.
2Area of stationary object
If the reading unit reads the entire original placement area including edge portions, then the area of readable region is improved, but the measurement precision deteriorates because the device cannot accurately distinguish between original content and black areas in corners
Solution Approach 1:
The patent implements feedback through image processing where the controller analyzes the scanned image data to detect black areas in the corner regions. The system uses this feedback information to determine whether to delete corner portions from the final image data, continuously improving the accuracy of the scanned output.
Solution Approach 2:
The patent applies dynamic corner shape estimation that adapts to different original types. The controller estimates corner shapes (rounded or sharp) based on the detected black area patterns in the scanned image, allowing the system to dynamically adjust its image processing approach rather than using a fixed method.
3Manufacturing precision
If the original holding sheet covers the entire original placement area, then the completeness of white background coverage is improved, but the ease of operation deteriorates because rounded-corner originals cannot be properly restrained
Solution Approach 1:
The patent changes the geometric parameter of the original holding sheet by rounding its corners instead of maintaining sharp corners. This modification enables the holding sheet to properly restrain rounded-corner originals (such as ID cards) while still providing adequate coverage, resolving the conflict between restraint effectiveness and coverage completeness.
4Loss of information
If the device deletes black areas from image data, then the purity of original image data is improved, but the difficulty of detecting and measuring increases because it is not easy to determine whether black areas are part of the original or artifacts
Solution Approach 1:
The patent applies local quality analysis by focusing specifically on the corner regions of the scanned image. The controller targets black area detection and deletion operations to the four corner areas of the original placement region, rather than analyzing the entire image. This localized approach reduces computational complexity while maintaining effective removal of artifact black areas.
Data Source
AI summary
A reading device includes: a reader; and a controller. The reader is configured to read both of a sheet of paper and a card as an original. The controller is, when the card having four original corners is set as the original, configured to perform for implementing a card reading function: (a) reading; and (b) acquiring. The (a) reading reads the original with the reader to acquire original image data corresponding to an original image area having four corner regions. The (b) acquiring acquires edge information of a first original corner from the original image data to estimate a round shape of the first original corner using the edge information. The first original corner being one of the four original corners in the original.