Image correction for perspective projection distortion of cylindrical surface

Abstract

To address the inaccurate measurement of cylindrical surface defects caused by perspective pro• jection in machine vision systems， an image correction method to resolve cylindrical surface perspective projection distortion is proposed. In this method， the image area of the cylinder is first extracted. Then， the transverse and axial directions are determined. On the basis of the perspective projection characteristics of the cylindrical surface， the distortion is divided into axial and transverse deformation. The imaging pa• rameters and cylindrical radius are utilized to establish the corresponding relationship between the coordi• nates of the original image and the those of the corrected image. The perspective projection distortion is corrected by pixel mapping and nearest neighbor interpolation. The experimental results demonstrate that the proposed method affords a good correction effect on images of different-diameter cylindrical surfaces.