Optical measurement support while creating visual and secondary secured NIR images

Darko Agić1, Silvio Plehati2, Tomislav Bogović2

1 Akademija tehničkih znanosti hrvatske
2 Fotosoft d.o.o.


One of the basic postulates of NIR theory for secondary mage creating are necessary twin colors. Those colors have important role as in visual part as in NIR domain. In visual they achieve the same visual response, although they do not have the same C,M;Y and K composition. This difference in twins has its ground by applying achromatic principles. Standard CMY inks in visual accomplish coloured experience by selective adsorption. In NIR domain they have relative small adsorption. Carbon black renders rather unifying adsorption through visual and nir domain, what leads to auxiliary separation and facilitates double image instrumental reading. Spectral photometers are crucial instruments. The visual domain facilities determine reflection/absorption characteristics and  support CIE colorimetry needed for twins quality. Forensic spectral device covering range of near UV to NIR is essentioal for extended area from visual to NIR. Analyse of absorption properties is of basic interest for distinctive disunion of images absorption curves and ΔZ definition.