Nonsubsampled contourlet transform method for optical fringe pattern analysis in profilometry and interferometry

摘要

A method based on a nonsubsampled contourlet transform, which is an overcomplete transform with multiresolution, directionality, and shift-invariance properties, is proposed to extract the fundamental frequency component of an optical fringe pattern in profilometry and interferometry. The nonsubsampled contourlet transform method overcomes the disadvantages of the original contourlet transform method, which lacks the shift-invariance property. Besides, it improves the frequency selectivity. A strategy is developed to automatically determine the optimal decomposition scale for removing the background intensity and suppressing the noise of the fringe pattern. The proposed method is precise, effective, and possesses a strong noise immune ability. Simulations and experiments verify the validity, and show the superiorities of the proposed method. (C) 2016 Optical Society of America