A method for correcting non-linear geometric distortion in ultra-wide-angle imaging system

Images of panoramic field of view obtained by ultra-wide-angle imaging system with large tilt angle will produce non-linear geometric distortion including radial and perspective distortion. In this paper, an integrated correcting method was proposed based on projective invariance property and planar template. The radial distortion is corrected by using the central points of planar grid template image, the cross-ratio invariability of collinear points, and the distortion parameters obtained by nonlinear optimization objective function. The perspective distortion is corrected by using perspective transform method. Experiments and analysis of non-linear geometric distorted images with different imaging modes suggested high accuracy of the proposed method. (C) 2013 Elsevier GmbH. All rights reserved.