Qualitative representation of scenes along route

This paper proposes a method for representing qualitatively a route in an o utdoor environment in terms of landmarks. A camera continuously scans the s ide-view and yields an intermediate representation called a panoramic repre sentation. The objects in the scene are segmented based upon range and colo r information in the panoramic representation, and they are then arranged i nto a structure map which provides qualitative information on the environme nt structure. The objects which have distinctive features along the route a re selected as the landmarks. When the same route is traversed again with a different camera speed, objects in the viewed scene are segmented and arra nged in a new structure map. Since their relative spatial arrangement is in variant with the camera speed, the stored landmarks can be matched with the objects in the new structure map by a dynamic programming method according to their depth and range along the route. The correctness of matching is f urther verified by comparing their disparity template. Results of experimen ts in both a scaled model and a real outdoor world show the effectiveness a nd robustness of this method. (C) 1999 Elsevier Science B.V. All rights res erved.