1. A method for producing a document representation from a bitmap image of a document, the method executing on a digital system, the digital system including a processor, memory, user input device and output device, the bitmap image of a document including a plurality of instances of a first text character and an instance of a second text character, wherein the bitmap image includes a plurality of pixels stored in the memory of the computer, the method comprising the steps of: detecting first, second and third instances of the first text character in the bitmap image; using the first, second and third detected instances to derive a first prototype character; detecting the instance of the second character; using the instance of the second character to derive a second prototype character; replacing each instance of the first character with the first prototype character to produce the document representation, the step of replacing includes the substeps of: (a) comparing the font of the instance to the prototype characters, the step of comparing the font comprising the following substeps: (1) examining the differences between each character in a word and the associated prototype character to distinguish words in different fonts; (2) determining a font difference for the entire word from the character differences; and (3) selectively using the original bitmap image of the word if the examined characters differ from their associated prototype characters by more than a predetermined threshold; and (b) only performing the replacing operation if the font of the instance is determined to be similar to the font of the prototype character; repeating the above steps for a plurality of subsequent documents; and for each of the plurality of subsequent documents, initializing the digital system before performing the above steps so that instances from prior documents will not affect the derivation of a prototype character.