Using collinear points to compute egomotion and detect nonrigidity

A novel approach to computing egomotion and detecting points not moving rigidly with the scene when an observer moves with unrestricted motion is presented. The approach, using collinear image points, is based on an exact method for cancelling effects of the observer´s rotation from optic flow. For each point only the component of velocity normal to the direction of the line joining the collinear points is needed. The algorithm is simple, appears robust, and is ideal for parallel implementation