Shape from Pattern Light Projection: Object Having a Diffusive and Specular Surface

We propose a depth evaluation method which utilizes a liquid crystal projector. The method is based on the phase shift technique. A sinusoidal grating pattern is used. The phase wrap problem is solved by the introduction of hierarchical pattern projection starting from one-cycle sinusoidal grating. We assume that the object have a diffusive and specular surface. Then the specular surface generates an area of highlights. The highlights may cause erroneous results on phase estimation. This paper describes the influence of highlights on the phase estimation. And confirmed that the influence is almost negligible except for the center of highlights.