Document monitoring method

摘要

A method of inspecting documents of value, the method comprises: a) obtaining images of one or more parts of the document from radiation received from that part or those parts of the document ( 14 ) in respective different wavelength bands; b) performing an analysis of one of said images to identify a first type of class within which the document of value is included; and c) performing an analysis of another of said images using corresponding predetermined data relating to members of the first type of class identified in step b) so as to determine a second type of class within which the document of value is included.