A system for recognizing and locating in an image, printed data of a known spatial characteristic. A digital matched filter is used to identify the presence of the printed data via an auto correlation between the filter coefficients and the printed data. When an auto correlation is identified, approximate...http://www.google.com.au/patents/US5563955?utm_source=gb-gplus-sharePatent US5563955 - Apparatus and/or method for recognizing printed data in an image
