Fringe-orientation estimation by use of a Gaussian gradient filter and neighboring-direction averaging.
We analyze the effect of image noise on the estimation of fringe orientation in principle and interpret the application of a texture-analysis technique to the problem of estimating fringe orientation in interferograms. The gradient of a Gaussian filter and neighboring-direction averaging are shown to meet the requirements of fringe-orientation estimation by reduction of the effects of low-frequency background and contrast variances as well as high-frequency random image noise. The technique also improves inaccurate orientation estimation at low-modulation points, such as fringe centers and broken fringes. Experiments demonstrate that the scales of the Gaussian gradient filter and the direction averaging should be chosen according to the fringe spacings of the interferograms.
Zhou
X
X
University of New South Wales, Australian Defence Force Academy, Canberra, ACT 2600, Australia. zhox95@octarine.adta.oz.au
Baird
J P
JP
Arnold
J F
JF