Edges and Contours

Abstract

Prominent image “events” originating from local changes in intensity or color, such as edges and contours, are of high importance for the visual perception and interpretation of images. The perceived amount of information in an image appears to be directly related to the distinctiveness of the contained structures and discontinuities. In fact, edge-like structures and contours seem to be so important for our human visual system that a few lines in a caricature or illustration are often sufficient to unambiguously describe an object or a scene. It is thus no surprise that the enhancement and detection of edges has been a traditional and important topic in image processing as well. In this chapter, we first look at simple methods for localizing edges and then attend to the related issue of image sharpening.