The subject of this thesis is to propose a robust edge detector based on the use of anisotropic Gaussian
kernels. Because of the high importance of edges in image processing, there exists many edge detection
methods. Among them, Canny edge detection method is most important. It is shown that the seminal
Canny edge detector may miss some obvious crossing edge details and the presented method overcomes
these difficulties. We begin with the use of anisotropic Gaussian kernel for noise suppression and
highlighting edges. Then, it is shown that why seminal Canny edge detector may miss some obvious
edges. Afterwards, based up on the use of anisotropic Gaussian kernel for noise suppression, a revised
edge extraction method is proposed. The experiment results show that the proposed algorithm can
obtain better performance for noise-free and noisy images.