| 摘要 |
<P>PROBLEM TO BE SOLVED: To accurately perform position cutout and letter recognition of a license plate at high speed by applying a matched filtering process. <P>SOLUTION: A plurality of templates of a license plate are prepared, an image obtained by photographing a road by a camera is inputted, the template is applied to the image, a correlation function between the template and the image is calculated, the template maximizing an evaluation value of the correlation function inside the image is specified, and an area corresponding to the template is cut out. Next, a plurality of letter templates (b) are prepared, an image (a) of a portion wherein the license plate is cut out from the image obtained by photographing the road by the camera is acquired, the letter template (b) is applied to the image (a), a correlation function g(x, y) between the letter template and the image is calculated, a search range (d) is set in each digit of a letter constituting the license plate, an evaluation value of the digit of the correlation function is found in the search range (d), the template maximizing the evaluation value is specified, and a letter corresponding to the template is recognized as the letter of the digit. <P>COPYRIGHT: (C)2006,JPO&NCIPI |
