Method and apparatus for identifying documents

摘要

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 test pattern satisfies a predetermined relationship with a predetermined pattern or patterns corresponding to a known document; and, if the predetermined relationship is satisfied, identifying the document ( 55 ) as being the same as the known document.