Note, that there also exists a possibility to calculate the center of mass using the `regionprops` function and the properties "Centroid" and "WeightedCentroid". But due to the label overhead this is probably a lot slower than your implementation.

Am Donnerstag, 30. August 2012 18:52:59 UTC+2 schrieb Luis Pedro Coelho:

Hello,

In the context of my previous email to pythonvision

https://groups.google.com/d/topic/pythonvision/SSCF4LUlRKQ/discussion

I made a timing comparison between mahotas & scikits-image.

operation | mahotas | pymorph | skimage
------------+----------+----------+---------
erode | 10.80 | 14.33 | 80.17
dilate | 11.44 | 8.93 | 41.59
open | 22.45 | 23.20 | 80.18
center mass | 7.05 | NA | NA
sobel | 75.03 | NA | 105.72
cwatershed | 201.03 | 56586.50 | 290.41
daubechies | 19.05 | NA | NA
haralick | 306.48 | NA | 7391.37

(Best viewed with fixed-width fonts)

The unit of measurement is the time it takes to run ``numpy.max(image)``
Mahotas is always faster than skimage (although pymorph is better for certain
morphological basic operations). I used GCLM in skimage to stand for Haralick,
which is a rough approximation.

I attach the script that generates these (against github skimage). If you
think that I have used skimage incorrectly, please let me know.

Best,
--
Luis Pedro Coelho | Institute for Molecular Medicine | http://luispedro.org