A quick method to obtain 3D surface data

Abstract

Fourier transform profilometry (FTP) based on fringe projection has high speed and high procession advantages, so it is widely used in industrial inspection, solid modeling, biomedicine, machine vision and so on. In this paper, we present a novel method, in which we project a bi-color fringe pattern that is consisted of two interlaced RGB base color fringe patterns with π phase difference onto the object using digital light projector and the deformed color pattern is captured by color digital camera. Then the deformed color fringe pattern is decoded into two individual fringe patterns with π phase difference using image-separating technique. After modifying their averages and contrast, we subtract one of the two fringe patterns from the other to eliminate zero spectra. Compared with π phase-shifting technique, the obvious advantage of this method is that only one fringe pattern is needed to remove the zero spectra and raise the measurable slope of height variation nearly three times while no phase shifting device needed. Computer simulation and experiments verify our method.