Interference fringe distortion correction method

Abstract

The present disclosure relates to the field of vibration non-contact measurement, and particularly to an interference fringe distortion correction method. The method includes: performing preprocessing on an interference fringe image, so as to eliminate interference of background light and high-frequency noise; calculating a gradient magnitude and a gradient direction in horizontal and vertical directions, respectively, and determining edges of interference fringes through double-threshold detection; determining a distortion type based on the edges of the interference fringes; obtaining a slope of a centerline of the interference fringes; locating a maximum response value through Fourier transformation; determining precise displacement through an extremum point of an interpolation function; and quantifying different interference fringe distortions into shift amounts through a phase correlation function, and performing reverse compensation correction. The present disclosure solves the problem that the interference fringe image distortion compromises detection accuracy of a coherent dispersive vibrometer through interference fringe centerline detection.