Here are a couple of early articles on the topic ... http://www.rit.edu/~andpph/text-agfa-1280-ir.html http://www.rit.edu/~andpph/text-ir-examples.html or http://www.rit.edu/~andpph/text-infrared-ultraviolet.html and another one http://www.echeng.com/photo/infrared/ regards, Andy