Naslov
Hidden information in paintings that manifests itself in the near infrared spectrum
(Skrivena informacija u slikarstvu koja se manifestira u bliskom infracrvenom spektru)

Autori
Žiljak Gršić, Jana ; Tepeš Golubić, Lidija ; Jurečić, Denis ; Matas, Maja

Izvornik
Informatologia (1330-0067) 52 (2019); 9-16

Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni

Ključne riječi
hidden information, paintings, near infrared spectrum (NIR)
(skrivene informacije, slikarstvo, bliski infracrveni spektar (NIR))

Sažetak
For each pigment and dye, we associate infor- mation about their absorption of light in the near infrared spectrum (NIR) at 1000 nm. Generally, pigments red, yellow, cyan blue, orange, white and “drap” (sandy brown) do not absorb NIR light. The NIR camera does not distinguish, rec-ognize or “see” them, so the NIR photo is white. Such colors are marked with the letter "V" (visual, VIS). The area of green pigments (in our lan-guage, “zeleno” = green) is very different consid-ering the absorption properties of NIR radiation. Some green pigments strongly absorb NIR radia-tion, while some green pigments absorb very lit-tle. That is why we have introduced the acronym Z as numerical information on the absorption of NIR light for all colorants, with a range from zero to ten. Painters are trained to mix colors with re-spect to their Z values. Dual images are pro-duced. The NIR camera separates the drawing, the image, depending on the amount of Z color. The painter succeeds in arranging the colors so discreetly that two images are taken in the same place, one of which is seen by the naked eye, while the other requires an NIR camera to be seen. The idea of a VIS / NIR painting is accepted with the realization that there are many video surveillance (NIR) cameras around us: on the streets, in restaurants, in banks, in public en- trances and entrances to private houses in gen- eral. The NIR design is used on documents, diplomas and banknotes as a general security method in graphic technology.

Izvorni jezik
Engleski

Znanstvena područja
Grafička tehnologija, Informacijske i komunikacijske znanosti

POVEZANOST RADA