Color fringe projection system based on optimum frequency selection

Zonghua Zhang; Catherine E. Towers; David P. Towers

doi:10.1117/12.679849

14 August 2006 Color fringe projection system based on optimum frequency selection

Zonghua Zhang, Catherine E. Towers, David P. Towers

Proceedings Volume 6292, Interferometry XIII: Techniques and Analysis; 62920S (2006) https://doi.org/10.1117/12.679849
Event: SPIE Optics + Photonics, 2006, San Diego, California, United States

Abstract

In this paper, we present a new color fringe projection system based on optimum frequency selection and discuss its implementation. Recent results in optimum frequency selection in temporal phase unwrapping have shown that the resolution limit of commercial data projectors is reached using 3 different sets of projected fringes with different pitch. Therefore, there is a synergy between optimum fringe projection and commercial color (RGB) projectors and cameras offering the potential for parallel data acquisition and simultaneous measurement of surface color parameters. The hardware of the system is comprised of a Digital Light Processing (DLP) video projector, a color 3-chip CCD camera and a personal computer supporting two monitors. The software is developed in Microsoft Visual C++ and OpenGL. The phase calculation algorithm is based on the optimum three-frequency selection, so it has a maximum reliability to determine the fringe order and can obtain 3-D shape of an object with large slope changes or discontinuities on the surface. Since each RGB color channel carries a fringe pattern of a certain pitch, any coupling between the color channels from the projector to the CCD camera affects the phase measurements obtained. Commercially available systems inherently contain crosstalk and we compare some methods to decrease the coupling effect. As absolute fringe order is determined by heterodyning between fringes with different pitch that are imaged in separate color channels, chromatic aberration can cause incorrect calculation of fringe order. We have investigated the most sensitive heterodyne process and the color channels with minimum chromatic aberration to mitigate these effects. We also give a novel software method to further compensate for chromatic aberration. Results show that our system has the advantages of fast acquisition, large dynamic range, robustness in discontinuities, and potential color extraction.

Citation Download Citation

Zonghua Zhang, Catherine E. Towers, and David P. Towers "Color fringe projection system based on optimum frequency selection", Proc. SPIE 6292, Interferometry XIII: Techniques and Analysis, 62920S (14 August 2006); https://doi.org/10.1117/12.679849

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available