Distortion Measurement and Calibration Technique Based on Phase Analysis for Carrier-fringe Pattern
基于载频条纹相位分析的畸变测量和校正

Abstract There is image distortion in optical digital imaging system. In order to measure and correct a distorted image, a new method is proposed: a vertical Ronchi carrier-fringe pattern is used as measuring template, and a distorted grating pattern is captured by the imaging system. Fourier transform method is adopted to analyze the spectrum of the distorted fringe pattern, and the fundamental spectrum is extracted by filtering; an ideal image is gotten from the central region of the distorted image, where there is no distortion, and the unwrapped phase distribution and radial wrapped phase distribution are obtained by fringe analysis; the radial phase distribution is converted the radial distortion distribution. Experimental results show that utilizing the radial distortion distribution and bilinearity interpolation, the corrected image is obtained, and the method is valid.