An Investigation into Temporal Gamma Luminance for Digital Fringe Fourier Transform Profilometers

Abstract

Analysis of the impact of temporal gamma luminance on Fourier transform profllometry (FTP) digital video projection (DVP) based structured light profilometers is undertaken. We investigate the spectral harmonic structure for typical DVP fringe images linking projector gamma and 2nd order fringe harmonics. The validity of the presented study is verified through simulation, and subsequently we conclude that for typical projector 7, the 2nd order harmonic is the single most significant contribution to reconstruction error for the phase measuring technique. The impact of our analysis is further gauged by empirical measurement of the temporal variation of gamma of a DVP device.