Patent ID: 8200016

Claim:
A method for character string recognition by processing image data obtained through picking up a character string placed on a medium comprising: processing the image data into black-and-white binary image data by using a prescribed reference threshold value for binary conversion; calculating vertical projection data of the binary image data in a vertical direction perpendicular to a direction of the character string while shifting the binary image data in the direction of the character string; detecting positions exceeding a prescribed border judgment threshold value in the vertical projection data as segmentation positions of characters included in the character string; judging validity of the border judgment threshold value according to the number of characters included in the character string; if the border judgment threshold value is judged to be valid, segmenting the characters out of the character string according to the segmentation positions of the characters, and examining characteristics of each character segmented; and if the border judgment threshold value is judged to be invalid, repeating the method from the step of processing the image data into black-and-white binary image data without segmenting the characters out of the character string.