Abstract
We propose a novel system for real-time three-dimensional surface orientation measurement. The advantages of our method are: 1) single frame capture of normal vector distribution, 2) dense, pixel-wise capture of normal vectors, and 3) independence of background illumination and surface reflectance nonuniformity of the object. This system consists of two components; one is sinusoidally amplitude-modulated three-phase (3P) light sources at vertices of a triangle and the other is the 3P correlation image sensor (3PCIS) for demodulating the amplitude and phase of reflected light on the surface. Based on the photometric stereo principle, the phase and amplitude can be easily converted to the orientation and inclination, respectively, of the surface. We implemented this system using our CMOS 32×32 pixel 3PCIS and successfully reconstructed the normal vector map. We also show several experiments for applying this system to personal identification by face.
