1. 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.