Low Cost Calibration of Stereo Line Scan Camera Systems

We present a new calibration method for 3d measurement systems consisting of two co-planar aligned line scan cameras. As appliance we use a calibration target whose geometric 2d and 3d parameters are only approximately known. As our input data we take from that target a sufficient number of single captured image lines in different geometric positions. Then we calculate 2d points within the joint viewing plane of the cameras both by triangulation of corresponding image points and by intersection with the lines on the target surface. The distances between the triangulation points and the related intersection points are minimized by linearizing and least squares adjustment. In the result we obtain all relevant parameters of the inner and outer orientation as well as the 2d and 3d geometry parameters of the calibration target with high accuracy.