Three-dimensional profilometry improvement based on grating projection

Grating projected method was used to measure the three-dimensional profile of smooth mouse. The traditional Fourier transform profilometry was improved. The signals were directly filtered without frequency shift after Fourier transform, then inverse Fourier transform was performed and the phase difference relative to the height was obtained. Compared with the traditional Fourier transform profilometry, the method removes three frequency shifts, greatly reduces calculation complexity and improves filtering accuracy. It takes 0.1 second to measure three-dimensional profile with the accuracy of 0.2 mm. The result indicates that the method could be used for smooth object measurement with good accuracy and efficiency.