Measurement of the 3-D shape of specular polyhedrons using an M-array coded light source

We reconstruct the shape of a specular object from the image of an M-array coded light source observed after reflection by the object. Using the "window property" of the M-array, a correspondence is found between a point on the image of the reflected light source and a point on the light source. By assuming that the local surface of the object is a plane, surface normal vectors are determined from the correspondence, and the three-dimensional shape of tile object is reconstructed. This method enables us to measure the shape of a specular polyhedron using simple equipment. The method was tested for a polyhedron with side length of 10 cm, set 50 cm from a camera. The shape of the polyhedron was reconstructed correctly. The measurement precision was about 1 mm.< >