Algorithm of differential operators in the edge detection of image and their comparison

The edge is the most basic of characteristic of image.The edge detection is an important step of image analysis and identification.So far,the edge detection method based on differential operators has been one of the most common ways in the edge detection of image.By the algorithm analysis of several differential operators such as Roberts,Sobel,Prewitt,Canny,Log,etc.and the MATLAB experience comparison,can be resulted that Canny and Log are more complicated than Roberts,Sobel and Prewitt in algorithm,but more exact in detection.The appropriate operator is chosen in accordance with different situation in use.