Hello all, Based on the discussion here: https://groups.google.com/forum/#!topic/pythonvision/AVrnueiKKYI It seems like this label function should be faster than the scipy version. However, I find it to be much slower: from skimage import morphology from scipy import ndarray as nd k = np.zeros((4000,4000),dtype=int) k[100,100] = 1 strel = np.ones((3,3)) %timeit morphology.label(k) 1 loops, best of 3: 1.46 s per loop %timeit nd.label(k,strel) 1 loops, best of 3: 355 ms per loop If you have any insight, I would be very grateful. I am using version 0.8.2 on the versions of python/numpy/cython, etc. included in the most recent edition of Enthought/Canopy. Thanks, Evan Daugharthy