Relaxation vs. maximal cliques search for projected beam labeling in a structured light sensor

A machine vision system based on a CCD camera combined with a light beams matrix is developed to output the 3D surface shape of vehicle cockpit occupancy. This paper focuses on the problem of image spots labeling. An initial set of possible spot/beam matching is deduced from epipolar constraints provided by the prior calibration of the relative camera/projector position. Then, using the topological constraints in the 2D mesh of illuminated dots, a constraint propagation process, based on relaxation or maximal cliques search, eliminates most of the possible combinations from the initial set of matching. Results of the labeling process, obtained by the two methods, are then discussed