Two practical issues in Canny's edge detector implementation
Gang Liu, R.M. Haralick · 2002
We address two practical issues, namely smoothing factor selection and efficient implementation of thresholding with hysteresis, in implementing Canny's edge detector. The smoothing factor of the Gaussian kernel should be chosen to maximize the discrete version of Canny's original criteria. Thresholding with hysteresis should be implemented using an efficient connected component analysis algorithm. Following these suggestions in implementing Canny's edge detector will in general result in optimal edge detection quality and very significant reduction in running time for large images.