Non conventional Imaging Systems for 3D Digitization of transparent and/or specular manufactured objects

3D scanning has been investigated for several years and most of the proposed approaches assume a diffuse or near diffuse reflectance of the object’s surface, also called cooperative surfaces. For the case of “non cooperative surfaces”, such as transparent objects or mirror-like surfaces, usually, a thin layer of powder is sprayed onto the object surface (to make it opaque and diffuse) prior to its digitization. This extra step is troublesome, time consuming (the object needs to be cleaned afterwards), and the final accuracy is often dependent on the powder thickness and its homogeneousness. To avoid this step, various methods have been investigated over the last few years. We propose in the paper to focus on three methods that we have been investigating over the last 10 years and compared their efficiency with those presented in the literature Keywords—3D Digitization, non diffused surfaces, Shape from polarization, Scanning from Heating, Shape from Induced Fluorescence.