Quantitative evaluation of the Reflectance Transformation Imaging and Normal Integration technique in profilometric application.

This article provides a quantitative analysis of the ability to faithfully reproduce the profile of objects using the Reflectance Transformation Imaging (RTI) coupled with Normal Integration technique. The study was conducted using ad hoc designed and built reference targets. It was possible to compare the profiles obtained using RTI technique with those realized using more conventional profilometric and 3D techniques such as micro photogrammetry, laser scanner and optical profilometry. It has been seen that the RTI technique is especially valid in the reproduction of high spatial frequencies and that it is very suitable for the study of cultural heritage, as it is portable, fast and low-cost.