A hybrid phase-unwrapping method for optical interferometry based on new parameter map and local plane approximation

摘要

Two-dimensional phase unwrapping (PhU) is one of the most important processing steps in optical phase-shifting interferometry. It aims to reconstruct the continuous phase field, but in fact, it becomes very difficult to perform the PhU due to the existence of noise, low modulation, under sampling, discontinuities or other defects. For solving the problem, we present a new PhU method which is based on the local parameter-guided fitting plane. It relies on the basic plane-approximated assumption for phase value of local pixels and is guided by our proposed parameter map-Modulation-Gradient and Pseudo-Correlation (MGPC) parameter map. This new map is the combination of fringe modulation and wrapped phase, thus it's reliable in estimating the quality or goodness of phase data. Meanwhile, the adoption of fitting plane for the 3?3 window of pixels makes the process of PhU very fast. In applications, we offer the simulated and the experimental data to compare our method with the two previously reported path-following unwrapping algorithms. The unwrapped results show our proposed PhU method not only is efficient, but also has higher noise robustness in recovering the true phase field.