Patent ID: 7415171

Claim:
A method for resolving an ambiguous character in a character string read by an OCR system, comprising: forming string permutations of the character string by substituting a plurality of replacement characters for the ambiguous character; deriving xgraphs from the string permutations, wherein deriving xgraphs comprises: dividing a string permutation into a set of multicharacter strings, each multicharacter string having a position in the string permutation; and categorizing the multicharacter strings according to position in the string permutation; matching the xgraphs with a reference set of valid xgraphs corresponding to the positions of the xgraphs in the string permutation; creating solution permutations by removing from the string permutations any string permutation containing an xgraph that does not match a valid xgraph in the reference set; and outputting the solution permutations.