2011/8/31 Claudio <claudyu...@gmail.com>: > Hi all, > I'm tring to implement a sobel filter using PIL library with few success. > > Now I never used this library before so any help is appreciate. > I wrote the following code that essential is a standard implementation > of the sobel filter: > > input img, output dimg: > dx = [-1, 0, 1, -2, 0, 2, -1, 0, 1] > dy = [-1, -2, -1, 0, 0, 0, 1, 2, 1] > > ximg = img.filter(ImageFilter.Kernel((3,3), dx, None, 0)) #apply the > kernel in x e y > yimg = img.filter(ImageFilter.Kernel((3,3), dy, None, 0)) > > dimg = img.copy() > dest = dimg.load() > xdata = ximg.load() #retrieve the x e y data > ydata = yimg.load() > > for y in range ( img.size[1]): # calcolo il gradiente per > ogni punto > for x in range( img.size[0]): > # dest[x, y] = sqrt( xdata[x, y] * xdata[x, y] + ydata[x, y] * > ydata[x, y]) > dest[x, y] = abs( xdata[x, y] ) + abs (ydata[x, y]) > > The result is not what I expected, so I misunderstood some function usage?
"not what I expected" is too vague. Maybe you have a 8 bits image and the convolution only uses 8 bits to store the results and then you get weird results ? -- -- Guilherme H. Polo Goncalves _______________________________________________ Image-SIG maillist - Image-SIG@python.org http://mail.python.org/mailman/listinfo/image-sig
