Robust phase unwrapping algorithm based on least squares

•A improved phase unwrapping algorithm by calculating coefficient k directly is proposed.•The new algorithm is applied to conventional least square phase unwrapping.•Our method improves the accuracy and reduces the time of phase unwrapping than before.•The new phase unwrapping method can unwrap the phase more rapidly and accurately.

We propose an improved phase unwrapping algorithm by calculating the unwrapping coefficient k directly based on a Least-Squares phase unwrapping algorithm. It can unwrap the phase more rapidly and accurately than most previous methods, especially for large grid phase unwrapping and where compulational cost is high. To validate this method, we performed a series studies using a conventional Least-Square phase unwrapping, conventional weighted discrete cosine transform (WDCT) and large grid phase unwrapping. Results show that our method not only improves the accuracy but also reduces the time of phase unwrapping.