Temporal phase unwrapping and its application in shearography systems

Temporal phase unwrapping is applied to a two-camera polarization phase-stepped system. A simple algorithm for the phase-change calculation is given, together with simulations, to indicate its validity and strength. This method can be applied directly for detection of phase changes as a function of time. It is proposed to use this method in a shearography setup. The phase distribution in the shearogram can then be obtained, without the standard 2pi ambiguities, by application of the required total shear in a number of smaller steps, provided that each step is small enough to be free from these 2pi phase steps.