A portable modular system for automatic acquisition of 3D objects

A portable and flexible system for three-dimensional (3-D) scanning is here presented. It is constituted of four main modules. The first module is devoted to the acquisition of a set of 3-D points over the surface through laser scanning (digitization). The second module reconstructs a continuous 3-D surface, filtering the measurement noise. Whenever required (e.g., in CAD applications), a third module converts the surface into a 3-D mesh which can then be colored by projecting over it a bitmap of the surface, obtained from a snapshot to obtain a highly realistic textured 3-D model. This instrument improves upon the commercially available scanners in two main aspects. The digitizer proves to be highly flexible and accurate, and it can easily accommodate objects of different dimension. The construction of the surface and the filtering of the digitization noise are performed in a single step through a fully adaptive algorithm which produces a multiscale surface and can be parallelized to work in real time. Results on the reproduction of human faces are reported and discussed.