Laser scanning for shape measurements

3D digital models have a variety of applications such as the realization of 3D catalogues and virtual museum, fast prototyping, restoration and architectural supporting and monitoring. This paper reports the preliminary results of a project regarding the development and the use of new technologies in the Cultural Heritage (CH) field. 3D graphics starts with the modeling stage, that is the realization of a digital representation of the object of interest. Classic 3D modeling tools are often inadequate to model the shapes in Cultural Heritage applications because of the shape complexity of most art works (e.g. sculptures and architectural mouldings) or the high accuracy required. 3D scanning techniques are sufficiently accurate to provide high fidelity reproduction of the shape of an object. These techniques have been adopted in a number of recent Cultural Heritage projects: the Digital Michelangelo Project of the Stanford University (Levoy et al., 2000), the acquisition of Michelangelo's Pietà in Florence by the IBM T.J. Watson Laboratory (Rushmeier et al., 1998), and the acquisition of a section of the Coliseum in Rome by an Italian research team (Gaiani et al., 2000). Laser scanning is probably the most versatile non-contact method for 3D measurements. Its main advantages are low cost, small size, high resolution and real-time response. In this paper we present a laser scanner system for Cultural Heritage applications and we also discuss the experience we get, the problems encountered during the development of our project and further possible applications of such 3D techniques in the restoration field.