Article

Visualization of additive-type moire and time-average fringe patterns using the continuous wavelet transform

Institute of Micromechanics and Photonics, Warsaw University of Technology, 8 Sw. A. Boboli Street, 02-525 Warsaw, Poland.
Applied Optics (Impact Factor: 1.78). 07/2010; 49(19):3640-51. DOI: 10.1364/AO.49.003640
Source: PubMed

ABSTRACT An application of the continuous wavelet transform to modulation extraction of additive moiré fringes and time-average patterns is proposed. We present numerical studies of the influence of various parameters of the wavelet transformation itself and a fringe pattern under study on the demodulation results. To facilitate the task of demodulating a signal with zero crossing values, a two-frame approach for wavelet ridge extraction is proposed. Experimental studies of vibration mode patterns by time-average interferometry provide excellent verification of numerical findings. They compare very well with the results of our previous investigations using the temporal phase-shifting method widely considered as the most accurate one. No need of performing phase shifting represents significant simplification of the experimental procedure.

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