An active method of extracting egomotion parameters from optical flow.

Instead of the former passive method characterized by a camera fixed on a translating and rotating vehicle, an active method characterized by tracking an object at the center of visual field is proposed. The method extracts egomotion parameters such as the instantaneous direction of translation, the axis of rotation and its angular velocity. A unit spherical surface is used as the projection surface. The theory allows clear vision where needed at the center of the visual field, and simultaneously permits the extraction of egomotion parameters from the periphery of the visual field.