Filter Dependence on the Phase Error of Fourier Transform Profilometry

Abstract

In phase measuring fringe reflection Fourier transform profilometry, it gets the captured image data from the projected sinusoidal fringe patterns by using the CCD cameras. Added white noise in captured fringe images and its low contrast levels affect the accuracy of three-dimensional surface profile measurements induced the phase errors. In this work, we present a phase error reduction method using the low pass spatial image filter and median filter. Experimental results have shown to validate the low pass filter and median filter. Although the effect of the filter is to be smoothed the fringe, white noise included in the pattern was able to remove effectively. In case of the median filter, it showed negative influence to the phase error, but the low-pass filter evidently reduced the phase error about 30%.