A method and apparatus for identifying a document (55). The method comprises exposing the document (55), such as a banknote, to infrared radiation; detecting infrared radiation reflected from a plurality of regions of the document (55) to generate at least one test pattern; determining if the or each...http://www.google.com/patents/US7266231?utm_source=gb-gplus-sharePatent US7266231 - Method and apparatus for identifying documents
