Direct egomotion estimation

In this paper, we address the problem of egomotion estimation for a monocular moving observer under arbitrary translation and rotation. This is a key step for the navigation of any autonomous system. The method proposed is uniquely based on the spatio-temporal image derivatives, and has O(n/sup 2/) complexity. We search the image for particular geometric properties of the normal flow, tightly connected to the egomotion parameters, in two successive steps. The /spl Psi/-line search algorithm determines the direction of the focus of expansion (FOE) and computes some information on the rotation parameters. Finally, the /spl Phi/-line search algorithm determines the FOE, and the individual values of the rotation. Various experiments with synthetic and real images are presented and discussed.