Robust phase demodulation algorithm for single-frame interferogram

This paper presents a robust phase demodulation algorithm (PDA) for single-frame interferogram based on preprocessing and watershed segmentation transformation. Compared to existing methods, the PDA can be applied to closed fringe or non-closed fringe patterns with low number of fringes indiscriminately. The proposed PDA includes two main parts, one is the preprocessing stage based on the empirical mode decomposition and Hilbert spiral transformation for background and noise removal, as well as normalization, and the other one is the correction of the wrapped phase obtained by arccosine through the watershed segmentation transformation. Through numerical simulations, the robustness of PDA to high noise and different kinds of fringe patterns is proved. The experimental evaluation of the proposed algorithm focuses on surface shape measurement of optical components, and the comparative analysis of the first 36 Zernike coefficients demonstrates that the PDA has high accuracy and the phase is good accordance with that obtained by phase-shifting interferometry.