Patent ID: 8184914
Filing Date: 2012-05-22
Classification: G06K

Abstract:
1. A computer-based method of comparing an image with a template image, the method comprising: deriving a normalized image based on the image; splitting the normalized image into rectangular blocks; representing the set of rectangular blocks of the normalized image by a DCT (discrete cosine transform); calculating a first distance between the normalized image and the template image based on a weighted sum of distances between corresponding blocks from the set of rectangular blocks of the normalized image and a set of rectangular blocks of the template image; comparing the first distance to a first predetermined threshold, the first predetermined threshold indicating a degree of similarity between the normalized image and the template; responsive to the first distance being greater than the first predetermined threshold, determining a set of overlapping blocks from the normalized image and representing the set of overlapping blocks by the DCT; calculating a second distance between the normalized image and the template image based on a weighted sum of distances between corresponding blocks from the set of overlapping blocks of the normalized image a set of overlapping blocks of the template image; and recognizing the normalized image based on the calculated distances.