The invention relates to an answer sheet identification method, which comprises the following steps: dynamically filtering and obtaining a colorful image of an answer sheet; carrying out gray
processing to the image; judging whether a gray image is the
processing of a "black" image; carrying out local threshold value binarization
processing; looking up to process a convex quadrangle on a
binary image, wherein the convex quadrangle has a maximum area and is more than a certain threshold value, and four inner corners of the convex quadrangle are similar to straight angles; carrying out inclination and
perspective distortion correction processing; intercepting a rectangular area, and carrying out normalized
image processing; identifying student numbers; identifying test paper numbers; and identifying answers. Due to the portability of a mobile terminal, a research that a mobile terminal camera is used for scanning an answer sheet and a relevant
algorithm is used for identifying becomes very meaningful, the working efficiency of a teacher can be obviously improved, and the answer sheet identification method is helpful for teaching work. The answer sheet identification method also can be used for reference into the identification
statistical processing of information cards, such as questionnaires, votes and the like, and has a wide application value.