Speckle-noise-reduction method of projecting interferometry fringes based on power spectrum density.
The fringe projection technique plays an important role in surface inspection, due to its noncontact, full-field acquisition and high resolution. When using projecting interferometry fringes, one of the basic problems encountered is the speckle noise existing in the fringe pattern. In this paper, a novel method is proposed to reduce the speckle noise based on power spectrum density (PSD) thresholding, which consists of three steps: first, PSD is calculated according to the frequency spectrum obtained by Fourier transform; second, a filter is constructed by a PSD thresholding to filter the frequency content of the speckle noise; and finally inverse Fourier transform is used to obtain the noise-reduction image. Experimental results prove the feasibility and effectiveness of the presented method.
The State Key Laboratory of Digital Manufacturing Equipment and Technology, School of Mechanical Science and Engineering, Huazhong University of Science and Technology, Wuhan, China.
Liping
L
Zhou
Jianghong
J
Gan
Xiaojun
X
Liu
Long
L
Xu
Wenlong
W
Lu