improc ass4: Added Cany edge detector file.

improc/ass4/canny.py

+#!/usr/bin/env python
+from matplotlib.pyplot import imread, imshow, show
+from scipy.ndimage import quiver
+from gauss import gD
+
+def canny(F, s):
+    pass
+
+if __name__ == '__main__':
+    from sys import argv, exit
+
+    if len(argv) < 3:
+        print 'Usage: python %s' % argv[0]
+        exit(1)
+
+    s = float(argv[2])
+    F = imread('cameraman.png')
+    E = canny(F, s)
+    imshow(E)
+    show()