Canny edge detector demos

There are some results of applying Canny edge detector to real image (The black and white image "lena.gif" we used here was obtained by translating from a color lena.tiff using matlab. So it might not be the standard BW "lena".) The thresholding parameter alfa is fix as 0.1. The size of the filters is also fixed as 10*10.

These images are all gray images though they might seem a little strange in your browser. To see them more clearly, just click these images and you will find the difference especially from the "result images", that is, the titled "after thinning" ones. The safe way to see the correct display of these images is to grab these images and show them by "xv" or "matlab". While, you are encouraged to use the given matlab codes and get these images in matlab by yourself. Try to change the parameters to get more sense about how these parameters affect the edge detection.

The results of choosing the standard deviation sigma of the edge detectors as 3.

lena.gif	vertical edges	horizontal edges

norm of the gradient	after thresholding	after thinning

The results of choosing the standard deviation sigma of the edge detectors as 1.

lena.gif	vertical edges	horizontal edges

norm of the gradient	after thresholding	after thinning