Car cockpit 3D reconstruction by a structured light sensor

A machine vision system based on a CCD camera combined with a light beam matrix is developed to output the 3D surface shape of vehicle cockpit occupancy. This paper focuses on the problem of image spots labeling: the matching between image spots and light beams is required for the triangulation procedure. The image spots are first extracted from the image. An initial set of possible spot/beam matchings 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 discrete relaxation eliminates most of the combinations possibilities from the initial set of matchings. From this matchings set, the 3D corresponding points are then computed via triangulation. Examples of 3D cockpit reconstruction are then presented.