A simple linear method to obtain height ordering of scene points

We present a novel algorithm to extract height ordering information for points relative to the ground plane. The ordering of scene points is obtained by exploiting the idea of linearly invariant representation of space points, image points, and the optical center of the camera, from which we derive a measure that is monotonic with respect to the height of points relative to the ground plane. We present results of the algorithm on data obtained from a mobile robot.