Shape measurements by sinusoidal phase-shifting methods require high-quality sinusoidal fringes. Furthermore, most of the video projectors are nonlinear, making it difficult to generate high quality phase without nonlinearity calibration and correction. To overcome the limitations of the conventional digital fringe projection techniques, we proposed a method that involves the projection of digital binary patterns generated by the pulse-width modulation (PWM). We will demonstrate that applying digital filtering, in particular, low pass filters, one can obtain a high-quality sinusoidal pattern. Which in combination with phase-shifting methods, allows a reliable 3-D profiling surface reconstruction at large timerates. Validation experiments using a commercial video projector are presented.

Date Published: 12 September 2014
PDF: 12 pages
Proc. SPIE 9219, Infrared Remote Sensing and Instrumentation XXII, 92190L (12 September 2014); doi: 10.1117/12.2062479

Published in SPIE Proceedings Vol. 9219:
Infrared Remote Sensing and Instrumentation XXII
Marija Strojnik Scholl; Gonzalo Páez, Editor(s)