基于载频条纹相位分析的畸变测量和校正

为了对图像畸变进行测量和校正,利用纵向朗奇(Ronchi)载频条纹作为测量模板,通过成像系统获取畸变光栅条纹.运用傅里叶变换对畸变条纹图像进行频谱分析、滤波提取基频信息,直接从畸变图像的中心无畸变区域提取理想条纹像信息.通过相位分析提取包裹相位并解包,获得畸变光栅条纹的径向畸变相位分布规律.将该分布规律转化为径向位置畸变分布规律,并结合双线性插值灰度重建对畸变图像进行校正.实验结果证明该方法是有效的.

Distortion Measurement and Calibration Technique Based on Phase Analysis for Carrier-fringe Pattern

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.