A Sub-pixel Edge Detection Method Based on Canny Operator

A sub - pixel edge detection method based on Sobel operator is discussed in this paper. First, the salt & pepper noise was added in the picture, and then median filter is used for eliminating the noise. Second, the probable position of image edge is determined by canny operator and then the edge detection has been achieved by a threshold which is getting from the maximal variance between-class method. Finally, implement interpolation to the edge of gray image by the third - order spline interpolation function. It make object´s edge located at sub - pixel level. Simulation result proves that this method can accurately locate object´s edge, which is better than the traditional edge detection method.