Edge detection based on directional space

Abstract

A new method for edge detection based on directional space is proposed. The principle is that: firstly, the directional differential space is set up in which the ridge edge pixels and valley edge pixels are abstracted with the help of the method of logical judgments along the direction of differential function, forming a directional roof edge map; secondly, step edge pixels are abstracted between the neighboring directional ridge edge and directional valley edge along the direction of differential function; finally, the ridge edge map, valley edge map and step edge map gained along different directions are combined into corresponding ridge edge map, valley edge map and step edge map. This method is different from classical algorithms in which the gray differential values of the mutual vertical direction are combined into one gradient value. The experiment of edge detection is made for the images of nature scenery, human body and accumulative raw material, whose result is compared with the one of classical algorithms and showing the robustness of the proposed method.