Building global object models by purposive viewpoint control

We present an approach for recovering a global surface model of an object from the deformation of the occluding contour using an active (i.e., mobile) observer able to control its motion. In particular, we consider two problems: (1) How can the observer's viewpoint be controlled in order to generate a dense sequence of images that allows incremental reconstruction of an unknown surface, and (2) how can we construct a global surface model from the generated image sequence? Solving these two problems is crucial for automatically constructing models of objects whose surface is non-convex and self-occludes. We achieve the first goal by purposefully and qualitatively controlling the observer's instantaneous direction of motion in order to control the motion of the visible rim over the surface. We achieve the second goal by using a calibrated trinocular camera rig and a mechanism for controlling the relative position and orientation of the viewed surface with respect to the trinocular rig.