Two-dimensional continuous wavelet transform algorithm for phase extraction of two-step arbitrarily phase-shifted interferograms

• 2D wavelet transform algorithm is used for analyzing phase-shifted interferograms.
• The algorithm requires only two interferograms whose phase shift can be arbitrary.
• The algorithm can handle interferograms with noise, defects, and complex fringes.
• Validity and practicability have been verified by both simulation and experiment.

By virtue of the anti-noise and anti-defect abilities, in this paper, a two-dimensional continuous wavelet transform algorithm is proposed to analyze two-step arbitrarily phase-shifted interferograms with an orthonormalization process. The novel algorithm takes the advantages of the two existing ones, and it has a remarkable ability to accurately and automatically extract full-field phase distribution from two phase-shifted interferograms where they may contain arbitrary and unknown phase shift, complex fringes with phase ambiguity, large fringe-frequency variations, noise, defects and corrupted fringes. The validity of the algorithm is demonstrated by both computer simulation and real experiments.