A multiple three-step phase shifting profilometry for nonlinearity error reduction

Abstract

We propose a method to reduce the phase errors due to intensity nonlinearity inherent to the traditional three-step phase shifting profilometry. In this method, multiple three-step phase shifting patterns with varying initial phase offsets were acquired. The height maps extracted from the multiple wrapped phase maps were averaged to get a more precise 3D profile of the object. We were able to reduce the ripples evident in the reconstruction of the conventional three-step phase shifting profilometry as we increased the number of sets of three-step phase shifting patterns to a certain value.