Fringe projection profilometry based on the best phase sensitivities

Abstract

In fringe projection profilometry, the phase sensitivity of a fringe pattern to depth variation of the measured surface is vital to measurement accuracy and resolution. This paper represents the implementation of the optimal fringe pattern with the best phase sensitivities over the whole fringe pattern, and deduces an efficient calibration method to determine the relationship between the phase-difference distribution and the depth variation. In it, first we find the epipole location by projecting sets of horizontal and vertical fringe patterns on several depth-known reference planes, and meanwhile determine the parameters of the measurement system calibration by analyzing the geometry of measurement system. And then project the optimal fringe pattern onto the object to measure. Experimental results demonstrate that this method is very efficient and easy to implement.