7. The method of claim 6, wherein the digital system comprises a fax machine and the portion of a document is derived from a fax transmission to the digital system.
6. A method for producing a bitmap document representation from a bitmap image of a portion 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 the portion of the document including a plurality of instances of a first character and a plurality of instances of a second character, the method comprising the following steps performed by the processor: detecting instances of the first character and instances of the second character in the bitmap image and storing the detected instances in the memory; using the detected instances of the first character to derive a first prototype character, wherein a bitmap of the first prototype character is a function of the bitmaps of the instances of the first character; using the detected instances of the second character to derive a second prototype character, wherein a bitmap of the second prototype character is a function of the bitmaps of the instances of the second text character; generating the bitmap document representation from the bitmap image by performing, for each character in the bitmap image, the following steps: (1) when the character is an instance of the first character, replacing a bitmap of the character in the image with a bitmap of the first prototype character; and (2) when the character is an instance of the second character, replacing a bitmap of the character in the image with a bitmap of the second prototype character; and outputting the bitmap image containing instances of characters replaced with bitmaps of prototype characters as the bitmap document representation.