Robust and fast filtering method for enhancement of two-dimensional quality-guided path unwrapping algorithms

This paper presents a new filtering algorithm for reducing phase noise based on the bicubic interpolation method (BIM). The unwrapped phase map accuracy is enhanced by the combination of BIM with a conventional unwrapping algorithm. The bicubic interpolation filtering (BIF) and bicubic interpolation smoothed filtering (BISF) methods are two powerful low-pass filters. The simulation shows that the BIF and BISF convert the initial noise distribution to Gaussian distribution. The Mirau interferometer is used to improve the performance of the proposed filtering algorithms. The root mean square error between two quality-guided path unwrapping algorithms and BISF method is estimated at approximately 31 nm.