Application of Non-Contact Methods for 3D Digitization of Sculpture and Watermark Embedding for Protecting a 3D Virtual Model from Abuse

Ovo istraživanje ima za cilj kreiranje pristupa za zaštitu virtuelnih 3D modela od zloupotrebe dostupnih širokom auditorijumu na internetu. Pristup predložen u istraživanju je primenjen na skulpturi, izabranom objektu od istorijskog značaja. Zasniva se na 3D digitalizaciji skulpture koja je izmenjena dodavanjem lokalnih detalja od gline, a koje je predložio vajar i na deljenju na internetu 3D virtuelnog modela dobijenog digitalizacijom skulpture sa ugrađenim zaštitnim elementom. Detalji od gline ugrađeni u skulpturu su asimetrični i diskretni da budu neprimetni prosečnom posmatraču. Originalna skulptura je takođe 3D digitalizovana i generisan je njen 3D model. Dobijeni 3D modeli su upoređeni i izmereno je odstupanje geometrije kako bi se utvrdilo u kojoj meri je ugrađeni zaštitni element neprimetan za prosečnog posmatrača, ali i da se taj element može detektovati i po potrebi ukloniti sa 3D modela sa ugrađenom zaštitom.This research aims to suggest an approach for protecting virtual 3D models from abuse while making them available on the Internet. The proposed approach was applied to a sculpture, an object of cultural heritage. It is based on the digitization of the sculpture altered by adding local clay details proposed by the sculptor and on sharing on the Internet a 3D model obtained by digitizing the sculpture with a built-in error. The clay details embedded in the sculpture are asymmetrical and discreet to be unnoticeable to an average observer. The original sculpture was also digitized and its 3D model created. The obtained 3D models were compared and the geometry deviation was measured to determine that the embedded error was invisible to an average observer and that the built-in error can be extracted