Itoh algorithm to unwrap 2D phase

Abstract

The fringes projection technique allows evaluating 3D profiles from testing objects without contact. To obtain those profiles it is necessary to get a photograph of the projected fringes. This image contains the information of the profile testing object as a deformation of the projected fringes. In order to evaluate the profile it is necessary to extract the phase from image fringes, usually this process requires an arctan()function. As is well known this function is limited by ±π and as a result the called wrapped phase is obtain. Therefore in order to get the real phase an unwrapping technique must be employed. In this work experimental and theoretical results of implementation of Itoh algorithm to unwrap phase are shown. This algorithm was written in MatLab and results show that this technique is suitable to measure profiles using fringes projection if images obtained are free of shadows or if the sampling satisfies Nyquist theorem.