Digitization of the collection of moldings of the university Marc Bloch in Strasbourg: a study case

3D digitization of middle size objects of cultural heritage is a problem that has been investigated many times for almost two decades. Recent works, for instance, have emphasized the complementarity of close range photogrammetry and terrestrial laser scanning. The goal is to generate a nice 3D model by realizing a feasible method which can be successfully applied regardless of the cost and sharp equipment needed. However, as soon as one wants to process a large collection of objects, the question of the standardization of the equipment as well as of the software becomes crucial. In the ideal case, one unique equipment and a small set of standardized treatments available in the commercial software should suffice to reach the goal at least for a category of objects. The museum of moldings of the University Marc Bloch in Strasbourg would like to digitize a significant set of statues that represent well classical Greek sculpture. In this paper, a method based on a terrestrial laser scanner designed to standardized software treatments is described. It is shown, in particular that the noise range that affects the measurement accuracy makes it impossible to obtain a correct surface triangulation. Thus, a method of spatial filtering is proposed. Its originality lies in the fact that it brings the problem back to the world of image processing. One can then envision to use the standardized image processing software to process the point clouds before surface triangulation. The work proposed in this paper shows that it is possible to obtain 3D models at reasonable cost which makes it possible to envisage semi-industrial production