关键词: 图像处理, 几何畸变, 校正算法, 灰度重建

Abstract: There is often some extent distortion existing in the short focal length and wide angle lens camera which is used for machine vision detection，in order to carry out high precision measurement，the lens distortion must be corrected first.A new method for distortion correction is proposed.It obtains the initial distortion coefficients by combining the optical image theory with distortion correction model at first，then the optimization function is used to find the optimal distortion coefficients，cubic B-spline interpolation method is adapted for gray rebuilding at last.Experiments indicate that this method shows perfect results，the radial correction RMS is 0.45 pixel and the gray rebuilding RMS is 0.36 pixel.

Key words: image processing, geometric distortion, correction algorithm, gray rebuilding