Descriptive contour fill of partly degenerated shapes

A uniform and consistent way of filling degenerated shapes on a raster grid is presented. The processing algorithms described are based on the contour segmentation of shapes along local minima and maxima (polysegments). To reduce errors, contour segments are scan converted by considering their real parameters. A criterion is introduced to find discrete departure and arrival pixels as well as the initial error for subsequent scan conversion of segments. The context-based description of potential polysegment and scan line intersections permits both the handling of singularities at birth and death points and the treatment of polysegment degeneration. The definition of degeneration and the execution of corresponding processing steps at segment, polysegment, birth and death point levels allows the contour filling of shapes scaled down by any factor