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| Design of Automatic Judgment System of Answer Card Based on Vision |
| CHENG Shu-hong,SHANG Guo-chao |
| College of Electric Engineering, Yanshan University, Qinhuangdao, Hebei 066004, China |
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Abstract Aiming at the limitation of function and price of cursor reader in the current market, a new method of answer cards recognition based on digital image processing is proposed. Firstly, the answer card is used for image pre-processing and graphic correction and the YCbCr color space algorithm is used to split out the candidate information area and answer information area. Then, the character matching and vertical synchronization-strips are used to locate their specific coordinates.Finally, the adaptive threshold algorithm is used to binarize the answer card and calculate the each filling area in binary image. Comparing the area with the set threshold, if it is bigger than set threshold, it will be regarded as having been filled. Experiments show that the method has higher recognition speed and accuracy. What’s more, it is not sensitive to the tilt of answer cards when scanning, and it has a better recognition effect on the size of the filling area, the unbalanced paintings, and the slight stains on answer cards, etc.
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Received: 11 September 2017
Published: 06 November 2018
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Corresponding Authors:
CHENG Shuhong
E-mail: shhcheng@ysu.edu.cn
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2018, Vol. 39 
