Adaptive Thresholding for Edge Detection in Gray Scale Images

Digital image processing is a subset of the electronic domain, wherein the image is converted to an array of small integers, called pixels, representing a physical quantity. Edges characterize boundaries and edge detection is one of the most difficult tasks in image processing hence it is a problem of fundamental importance in image processing. The problem of edge detection although it is fundamental and is existing since years but it is still an area where there is still scope of research. It has been found that the previous used algorithms or methods were not able to produce ideal or optimized results. This paper presents an edge detection method applicable to gray level images in which an objective function is used to extract edge points as well as their directions. Adaptive thresholding technique is used there after to suppress non maximum points and to highlight edge points.