In this work, we presented a phase demodulation technique for fringe analysis in fringe projection profilometry based on digital moiré and the co-phase technique. The approach involves the use of stereo illumination and the simultaneous projection and acquisition of two π-shifted sinusoidal patterns from each projector. By taking advantage of color multiplexing, we code the sinusoidal patterns in the red and blue channels of the RGB images, so we need to project and acquire one image for each digital light projector. The phase demodulation consists of two steps: first, digitally generating the moiré pattern for each RGB image utilizing the spatial phase carrier; second, computing the analytic signals for the two moiré patterns via a third-order, low-pass Butterworth filter in the frequency domain; third, calculate the final phase by merging the two analytic signals using the co-phasing technique.
We introduce a modifying deflectometry method to reduce parasitic ghost signal noises in transparent optical testing. The proposed approach shows adjusting the screen distance and displayed screen pattern to shrink the light from undesired surfaces’ reflection. The flexibility of deflectometry optical layout allows huge adjustment availability while keeping the optical testing capability and suppressing the parasite signal. Moreover, the customized fringe pattern could shine the desired surface only effectively. Ray tracing simulation shows the best system formation, and the modified experimental setup confirms the proposed method for various types of optics testing. Lastly, we discuss the limitations of the method.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
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.