US 6,687,697 B2 · System and method for improved string matching under noisy channel conditions

Abstract

Described is a system and method for improving string matching in a noisy channel environment. The invention provides a method for identifying string candidates and analyzing the probability that the string candidate matches a user-defined string. In one implementation, a find engine receives a query string, converts an image file into a textual file, and identifies each instance of the query string in the textual file. The find engine identifies candidates within the textual file that may match the query string. The find engine refers to a confusion table to help identify whether candidates that are near matches to the query string are actually matches to the query string but for a common recognition error. Candidates meeting a probability threshold are identified as matches to the query string. The invention further provides for analysis options including word heuristics, language models, and OCR confidences.

Claims25

Dependent claims

A computer-readable medium having computer-executable components for locating a query string in a document image file, comprising:

a search component in communication with an image file and being configured to transform the image file into a textual file, the textual file including textual data corresponding to graphical representations of the textual data within the image file;
and
a confusion table identifying errors that could occur during the transformation of the image file to the textual file, each error in the confusion table having an associated likelihood that the error would occur,
wherein the search component is configured to locate instances of a query string within the textual file by comparing the query string to a candidate string in the textual file and determining a probability that the candidate string matches the query string and using the confusion table.

1 more element

A computer-implemented method for locating strings in a document, comprising:

receiving a request to locate instances of a query string in a document image file;
transforming the document image file into a document text file using a recognition process;
performing a fast approximate string match on the document text file to identify a candidate data string that differs from the query string by less than a predetermined factor;
and
analyzing the candidate data string to identify a probability that the candidate data string matches the query string.

2 more elements

Dependencies are inferred from the claim text.

System and method for improved string matching under noisy channel conditions

Life of this patent

System and method for improved string matching under noisy channel conditions

Life of this patent

Abstract

Claims25