Patent ID: 8249364
Filing Date: 2012-08-21
Classification: G06K

Abstract:
1. A method for resolving contradicting output data from an Optical Character Recognition (OCR) system, wherein the output data comprises pixel images of characters as they have been encountered in an image of a text document being processed by the OCR system, and wherein a first subset of the output data represents images of characters that have been recognized to a degree of certainty above a predefined level, and wherein the output data further comprises a second subset of characters comprising at least a first candidate character image and a second character image being identified as being substantially equal probable identifications for a same exemplar of a sampled character instance from the text document being processed by the OCR system, the method comprises the steps of: a) searching through the first subset of the output data identifying images of characters having an image quality above a predefined level, and using these character images as a set of template images for characters, b) comparing the first candidate character image and the second candidate character image with each of the respective template images identifying a first template image representing the first candidate character image and a second template image representing the second candidate character image, respectively, c) comparing the first template image with the second template image identifying a first displacement between these images, and aligning the first template image relative to the second template image according to the first displacement, d) identifying locations of areas comprising features differentiating the first template image form the second template image in the aligned images, expressing the location information of these areas relative to the aligned images, e) comparing the image of the sampled character instance with either the first template image or the second template image identifying a second displacement , and then aligning the image of the sampled character instance with either the first template image or the second template image according to the second displacement, f) using the location information from d) to identify corresponding areas in the aligned image of the sampled character instance, and then comparing image contents of the located areas by calculating mean values of the pixel values comprised in the located areas of the sampled character instance and then subtracting these respective mean values, wherein the result of the subtraction together with the actually selected template image used when identifying the second displacement provides a criterion for selecting either the first candidate character or the second character candidate as the identified character for the sampled character instance.