Analysis and development of image edge detection techniques

Abstract

Edge detection is the process that attempts to characterize the intensity changes in terms of the physical processes that have originated them. Edge detection can be used for region segmentation, feature extraction and object boundary description. Edges provide the topology and structure information of objects in an image as different cars can be easily recognized from their body shape. The highway and river from aerial images can be detected in terms of their structure or distribution pattern, which are described by edges. By using edge detection techniques, machine vision and image processing systems can be built for a variety of applications. For example, edge detection can be used in assembly line inspection to detect defects of mechanical parts, for locating the road and recognizing obstacles in automatic vehicle navigation and to detect military targets in remote sensor applications. For medical imaging applications, edge detection and boundary segmentation can be used for locating tumors, blood vessels and rigid bony structures. The separation of a scene into object and its background is an essential step in image interpretation. This is a process that is carried out effortlessly by the human visual system, but when computer vision algorithms are designed to mimic this action, several problems have been encountered. This research work first analysis the goals of edge detection, some basic issues in edge detection and various techniques of edge detection in the literature. During edge detection it is possible to locate intensity changes where edges do not exist due to the presence of noise and quantization of the original image. For similar reasons, it is also possible to completely miss existing edges. The degree of success of an edge-detector depends on its ability to accurately locate true edges.Edge localization is another problem encountered in edge detection. The addition of noise to an image can cause the position of the detected edge to be shifted from its true location.