Range sensors on marble surfaces: quantitative evaluation of artifacts

摘要

While 3D imaging systems are widely available and used, clear statements about the possible influence of materialproperties over the acquired geometrical data are still rather few. In particular a material very often used in CulturalHeritage is marble, known to give geometrical errors with range sensor technologies and whose entity reported in theliterature seems to vary considerably in the different works. In this article a deep investigation with different types ofactive range sensors used on four types of marble surfaces, has been performed. Two triangulation-based active sensorsemploying laser stripe and white light pattern projection respectively, and one PW-TOF laser scanner have been used inthe experimentation. The analysis gave rather different results for the two categories of instruments. A negligible lightpenetration came out from the triangulation-based equipment (below 50 microns with the laser stripe and even less withthe pattern projection device), while with the TOF system this came out to be two orders of magnitude larger,quantitatively evidencing a source of systematic errors that any surveyor engaged in 3D scanning of Cultural Heritagesites and objects should take into account and correct.