Abstract: A method for measuring the contour of a surface using a high intensity light source, optics for projecting a line of light on the surface to illuminate a selected contour feature of the surface, an optical detector which generates an image of the selected contour feature, and a processing unit which fits at least one contour segment to the image of the selected contour feature and determines contour characteristics from the contour segment. The method includes a calibration step which corrects for distortion and keystone effect in the image caused by off-axis imaging of the illuminated contour feature by adjusting vertical and horizontal grid lines of an electronically created image with the off-axis image of the contour surface.