The application of vectorization algorithms to digital images derived from natural scenes is discussed. It is argued that the fractal nature of these scenes precludes some of the savings in storage expected from vector over raster representation, although considerable savings still result. Experimental results are given. Algorithms for contour following, line thinning, and polygonal approximation well adapted to complex images are presented. Finally, the Map Manipulation System, an experimental program package designed to explore the interaction between vector and raster information, is described briefly.