An extension of Marr's signature based edge classification and other methods determining diffuseness and height of edges, and bar edge width

The authors classify edges with respect to diffuseness and profile type by using a tool evolved from scale space methodology called signatures. The method also enables the user to measure degree of diffuseness, height of edges, and bar edge width. The Gaussian difference signatures and apparent width signatures used are defined. To sift out the major edges, subsets of edge pixels must be selected. For describing the local gray level, landscape averaging needs to be done in a noncommittal fashion, as opposed to fitting a specific function blindly to data. Edge focusing, which is a coarse-to-fine traversal of brightness changes, deals with the subsets, whereas signatures may be thought of as a kind of reasonably cleverly done averaging. This method is of importance for distinguishing between illumination phenomena and object edges, performing depth-from-focus in single images, and in junction analysis. >