Raster and vector processing for scanned linework

The conversion of raster linework to vector chains or arcs is investigated using various raster editing techniques. The techniques of thinning, filling, and node detecting are based on encoding the state of a 3 x 3 neighborhood surrounding each pixel into a single byte. These raster operations were applied to a digital elevation model and a portion of a topographic map. The automated parts of the raster-to-vector process are discussed. It is noted that by using several image-processing and vector-editing techniques, raster lines can be converted to vector arcs.