Patent ID: 8285074

Claim:
A method of generating image anchor templates from low variance regions of document images of a first class, wherein the document images of the first class is a collection of document images of a same type, said method comprising: selecting a document image from the document images of the first class; aligning the other document images of the first class to the selected document image, the aligning comprising: selecting a plurality of sub-regions from each of the other document images; determining a best match in the selected document for each of the selected sub-regions of the each of the other document images; determining a transformation for the each of the other document images using a least squares analysis to minimize the difference between the best matches of the selected sub-regions of the each of the other document images and the selected sub-regions of the each of the other document images; and transforming the each of the other document images according to the determined transformation of the each of the other document images; determining the low variance regions by comparing the aligned document images and the selected document image, wherein the low variance regions are those regions that vary little between the selected document image and other document images; and generating image anchor templates from the determined low variance regions, wherein the method is performed using at least one digital processor.