Study on the Method of Extracting Phase Using the Fourier Transform

A new method of extracting interference fringe phase is proposed. Firstly, the interference fringe was transformed from the spatial domain into the frequency domain using the Fourier transform. The positive spectrum carried the wave-front information. Secondly, the digital filters were design to filter the zero and negative spectrum through the weighted filter, and then the wrapped phase was obtained using the inverse Fourier transform. Finally, based on the analysis of various unwrapping algorithms, the idea of the correction after the unwrapping was given to solve the problem of error point. The research results show that the method is simple and applicative, and is proved effective for most of the patterns.