A robust image processing approach used for ALV (autonomous land vehicle) road following is presented. The approach can cope with illumination variation, bad road surface condition such as shadows, defects, dirt and water stains. And it is effective for images of multi-branched road intersections. The approach consists of key techniques: color band automatic selection; adaptive road area segmentation; binary image post-processing and knowledge-based road trend line fitting. The approach is easy to implement in real time because its processing stages can be arranged into a pipeline. A set of experimental results is also presented.>

We present a novel approach for finding corresponding points between two line drawings extracted from perspective views of a moving object whose surface is composed of planar polygons. In our approach, each circuit of the drawings is encoded with a boundary shape code which we call the RLCC code (run length code of convex and concave strings), then a clustering technique is used to obtain the matching result recursively. A series of measures are taken to make the algorithm tolerate considerable dissimilarities which may exist between the two drawings, such as missing lines, scale differences, rotation, perspective shape distortions, etc. Experimental results are presented.

To extract line drawings with positional information from perspective veiws of three-dimensional objects is essential in image analysis and understanding. A new heuristic-search algorithm driven by a priori knowledge contained in a world model is presented which extracts a connected line drawing from a perspective view of a polyhedron. A main feature of our algorithm is that the search is concentrated on local areas centered at corners found with a corner finder. Therefore, the search time is significantly reduced and so are the positional errors in the extracted line drawing. An iterative process removes the false corners and lines and thus guarantees that our algorithm will work stably and reliably even in a noisy environment. Experimental results are presented.