W e summarize our recent novel approach to computing the Focus of Expansion for an observer moving with unrestricted motion in a scene with objects of unrestricted shape. This method also detects points not moving rigidly with the scene. The approach, using collinear image points, is based on an exact method for cancelling effects of the observer's rotation from optic flow. The computational results are being presented elsewhere (da Vitoria Lobo & Tsotsos 1991). Here, we argue that this algorithm is biologically plausible.
