Abstract
The photometric stereo method is extended for single-frame, disturbance illumination free measurement of normal vector map. This system uses (1) three-phase amplitude-modulated illuminations at the vertices of a regular triangle and (2) correlation image sensor (CIS). The triangular three-phase amplitude-modulated illuminations are used to encode the surface orientation into the amplitude and phase of the reflected light intensity. The CIS demodulates them and reconstructs the surface orientation. Based on the correlation detection principle, any background illuminations uncorrelated with the modulated light are satisfactorily removed. The normal vector map as well as the intensity image are obtained in a single frame. Several experimental results for the system performance evaluation are shown.
