Aryan Abbaszadeh - Electrical and Computer Engineering faculty University of Tabriz
Sabalan Daneshvar - Electrical and Computer Engineering faculty University of Tabriz

Edges are prominent features that specify the boundary between two differentregions in an image. Edge detection algorithm reveals the sharp discontinuitiespoints. This processor reduces the useless information while preserving thesignificant structure . There are a lot of different methods to detect the edge ofimages that have been proposed over the past years. However, they cannot stillfind an algorithm with a strong response to edges. This paper reviews three maincategories of edge detection techniques including differentiation, Waveletstransform, and Gabor Filters. In the study, the advantages and disadvantages ofthese algorithms are investigated and compared. Some of the researchers havecombined these methods with each other and their effects have usually shownbetter results. After research about these methods we concluded that, the thirdcategory is appropriate for real images containing several noises. These groupsalso have resemblance to human visual system and can extract local feature suchas edges, and the tissues of images.

Image Processing , Edge Detection , Wavelet transforms , Gabor filters