Performance Analysis of Image Edge Detection using Hybrid, Sobel and Log Sobel Methods

Image Enhancement is one of the first steps in Image processing. It is a cosmetic procedure, i.e. it does not add any extra information to the original image. It merely improves the subjective quality of the images by working with the existing data and is used for improving the interpretability or perception of information in images for human viewers. In this project, hybrid approach and Log-Sobel algorithm are used to perform edge detection on images. Edge detection aims at identifying points in a digital image at which the image brightness changes sharply or, more formally, has discontinuities. By using a hybrid approach, simultaneous adjustment of contrast and boundary enhancement can be done. In Log-Sobel method, processing of an image is done with the logarithm of luminosity not with luminosity. The Histogram has been plotted to verify the result of various edge detection techniques. T h e Log-Sobel method can be considered as better edge enhancement technique than the Sobel method as the texture is clear and the effect is obvious. It can enhance the Peak signal-tonoise ratio. As medical image processing plays an essential role in providing information on wide area for advanced images, Log-Sobel method can be used for enhancing edges of MRI brain images, MRI knee images, etc. Keywords—Image Enhancement; Edge detection; Log Sobel Operator; contrast stretching; laplacian mask ;Simulation.