1. A method for identifying a character printed on a document comprising the steps of: generating an analog signal representative of said character as the document passes a read element; digitizing and storing values representing said analog signal for said character; locating positive and negative peaks associated with said analog signal for said character; testing the peaks associated with said character against a first plurality of repeating patterns, having different combinations of period and offset between positive and negative peaks, to determine which of said first plurality of repeating patterns best fit the peaks stored for said character; using the one of said plurality of repeating patterns which best fits the peaks to select at least some of the stored digitized values and, testing said selected stored digitized values against a second plurality of patterns representing the set of characters which can be identified, to identify the character.