Method of ocr template enhancement by pixel weighting

Abstract

A library of L unenhanced images (pixel bit maps) is enhanced for optical character recognition (OCR) with respect to a pre-existing group of G input symbols (pixel bit maps) for creating a library of G recognition enhanced templates (pixel bit maps) of the G input symbols. The enhancement is accomplished by comparing each image of the library with each symbol of the group, and weighting the images with the highest potential for confusion. A primary comparison C* and a secondary comparison C** are identified from the L comparisons within each of the G sets of comparisons. A recognition margin is determined between each pair of identified comparisons C* and C**. The single pair of identified comparisons C* and C** is selected forming the smallest recognition margin M*. The single pair of images I.sub.j * and I.sub.j ** underlying the pair of identified comparisons C* and C** is identified. Certain pixels of the closest pixel image I.sub.j * and the next closest pixel image I.sub.j ** are weighted in order to increase the recognition margin M* therebetween. The steps are iterated until the library of pixel images has become a library of sufficiently enhanced symbol templates. The weighted pixel abberations generated in the enhanced templates are not present in the corresponding pixel symbol of the pre-existing group of G pixel symbols.