Comparing digital-light-processing (DLP) and liquid-crystal-on-silicon (LCoS) technologies for high-quality 3D shape measurement

This paper presents a thorough comparison between the digital-light-processing (DLP) technology and liquid-crystal-onsilicon (LCoS) technology on high-quality 3D shape measurement. Specifically, we will study not only each individual color, but also the combination of different color (i.e., white light). The binary defocusing and focused sinusoidal fringe projection methods will be evaluated under all these scenarios. Experimental data demonstrated that for slow speed measurements, DLP has better fringe contrast and thus higher signal to noise ratio (SNR) for better quality 3D shape measurement when the binary defocusing method is employed, or when proper synchronization is present when the focus sinusoidal method is used; and LCoS provides more flexibility for system development when the focus sinusoidal method is employed.