A Method for Obtaining Basic Frequency of Grating Image in Fourier Transforms Profilometry

摘要

In order to obtain the useful basic frequency easily and reduce the loss of image energy in the Fourier transforms profilometry, the multi-scale character of wavelet transform is used to separate the direct current part and the basic frequency in this paper. Then the handled grating images are filtered according to the number and features of noises. The simulation test indicates that the choice of filter window and the level of wavelet decomposing scale are important. And the method is tested effective in this paper.