A method of automatic recognition for answer sheet

The traditional method of recognizing an answer sheet is to use optical mark reader (OMR). A kind of OMR only recognizes a certain answer sheet with fixed format, which results in the poor universality of OMR. We propose a recognition method for answer sheet with arbitrary format. After designing the new answer sheet or using the existing ones, the printed answer sheets will become images by high-definition (HD) scanning after being filled in an exam. And the images of answer sheets will be recognized automatically by image processing techniques. According to the positioning cross found in answer sheets, the images will be corrected if they are tilted. Then candidate number recognition, option recognition and page number recognition will be carried out in the order specified by users. The method of maximum between-cluster variance will be used for candidate number recognition and option recognition. On the other hand, the page number of answer sheet will be recognized by template matching. Experimental results show that the accuracy can reach 100%. And this method can be realized easily, the cost is low, and it has good universality.