Performing a comparison between two images which are scaled to a common resolution

摘要

A system and method for comparing digital images, such as checks images used by banks, includes receiving and processing the images to be compared, including scaling the images to a common resolution, as well as filtering them to remove spot noise, background pels, and other non-information carrying elements. One or more regions of each image are selected for comparison. The selected regions are compared to one another by subtracting the pels of one image from the other's pels. A determination is made of whether the two or more images are duplicates of one another, or depict a substantially identical subject, based on the results of the subtractions. Furthermore, the amount of filtering and scaling may be adjusted to enhance the effects of the system to take advantage of common characteristics that may be known or detected in a particular set of images to be compared.

主权项

1. A system for comparing images, comprising:
a computer having a processor, and a computer-readable storage device; a program embodied on the storage device for execution by the processor, the program having a plurality of program modules, including:
a receiving module configured to receive a first image and a second image;a processing module configured to process the first image and the second image, wherein the processing includes scaling the first image and the second image to a common resolution;a selecting module configured to select one or more pel regions of the scaled first image and of the scaled second image;a subtracting module configured to subtract the one or more selected pel regions of the scaled first image from the one or more selected pel regions of the scaled second image, respectively; anda determining module configured to determine whether the first image and the second image depict identical subjects based on results of the subtracting module, wherein the processing module is further configured to filter at least one of the first image and the second image, and wherein one or both of the first image and the second image are bitonal, having black pels and white pels, and the processing module is further configured to filter the first image and the second image by removing black pels or groups of black pels surrounded by white pels, and the black pels or groups of black pels exist in a square grid having the size 1 by 1 pels to 4 by 4 pels, preferably having the size 3 by 3 to 4 by 4 pels.