Abstract
Edges characterize boundaries and are a problem of fundamental importance in image processing. Edge detection of images reduces the amount of data and filters unwanted information and preserves important structural properties of images. Edge detection is a process of locating boundaries of objects or textures present n an image. Data of edge detection is very large, so the speed of image processing is a very difficult problem. There are many techniques used for the purpose of edge detection depending upon the requirement of various applications. This paper provides an extensive review of various research work and methodologies which are applied in the field of edge detection.