Description and reconstruction from image trajectories of rotational motion

A novel technique is presented for reconstructing the 3-D structure, and motion, of a scene undergoing relative rotational motion with respect to the camera. Given image correspondences of point features tracked over many frames, first, a grouping algorithm developed which exploits spatio-temporal constraints of the common motion to achieve a reliable description of discrete point correspondences as curved trajectories (general conics in the case of rotational motion) in the image plane. In contrast, trajectories fitted to points independent of each other lead to arbitrary image descriptions and very inaccurate 3-D parameters. Second, a novel closed-form solution, under perspective projection, for the 3-D motion and location of points from the computed image trajectories is presented. Both stages are applied to real image sequences with good results