Method for improving sinusoidal quality of error diffusion binary encoded fringe used in phase measurement profilometry

Insufficient resolution of digital-light-processing projector will degrade the sinusoidal quality of the binary encoded fringe pattern because of less sampling points in a fringe period, which will degrade the measurement accuracy if it is used in phase measurement profilometry. Two resolutions are proposed in the paper. One is that a cylindrical lens is introduced in the projecting light path of the measurement system to improve sinusoidal quality of the binary encoded fringe by elliptical low-pass filtering of the system. The other one is that superposition of multi-frame binary encoded gratings with different microstructure is to reduce the binary image noise for improving the measurement accuracy. Simulations and experiments verify the validity of the above two methods.

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Opracowanie ze środków MNiSW w ramach umowy 812/P-DUN/2016 na działalność upowszechniającą naukę.