Phase-shifting grating projection moire topography

Abstract

A phase-shifting projection moire method particularly intended for high-speed three-dimensional inspection of fine objects is presented. Emphasis is on realization of phase-shifting fringe analysis in projection moire topography using a set of line grating pairs designed to provide different phase shifts in sequence. Further, a time-integral fringe capturing scheme is devised to remove undesirable high-frequency original grating patterns in real time without time-consuming software image processing. Finally, the performances of the proposed method are discussed with measurement results. (C) 1998 Society of Photo-Optical Instrumentation Engineers. [S0091-3286(98)03503-X].