LOW COST SOLUTIONS FOR DENSE POINT CLOUDS OF SMALL OBJECTS: PHOTOMODELER SCANNER VS. DAVID LASERSCANNER

The study of archaeological artifacts requires a great care for the object. Current technologies allow the study of the object scanned in three dimensions. Hence, the digitization of objects has almost become compulsory for simplicity of study and analysis. For each scale of objects, dedicated hardware equipments exist oftentimes at important costs. Among others, scanning arms, handheld scanners, triangulation scanners, terrestrial laser scanners offer a wide variety of possibilities to produce 3D data. However, the question of cost is central in the field of archaeological research. That is probably why the technology is not widely spread in the community. Besides, the question of knowhow is also an important issue. Despite the appearances, a 3D digitization project is not so easy to carry out. Hence a low cost solution susceptible of being operated with reasonable effort could contribute to popularize 3D acquisition tools. In our study, we focus particularly on two solutions: David Laserscanner and PhotoModeler Scanner. Both systems come from two different techniques: laser scanning and photogrammetry. They can both produce dense clouds of points of small objects. Our comparison is completed according to several criteria. The most important criterion is undoubtedly accuracy; it is therefore significant to quantify the ability to produce a reliable point cloud. To compare the point clouds obtained with both systems, we use a point cloud provided by an arm scanner whose accuracy is less than 1/10th of a millimeter. As a second important criterio