Runnig Z Projector plugin

[lechristophe]

Dear all,

I'm trying to use Nico Stuurman's Runnig Z Projector plugin in a macro :
http://valelab.ucsf.edu/~nico/IJplugins/Running_ZProjector.html<http://valelab.ucsf.edu/%7Enico/IJplugins/Running_ZProjector.html>

On the plugin web page it states "This plugin calculated a runnings average
from the data in a stack. The images in layer 1-n (n is user-specified) are
combined using the user specified method, this is repeated from image
2-(n+1), etc..". Assuming "1-n" means "from layer 1 to layer n", my guess
would be that from a stack with N slices with a user specified n, you get an
averaged stack of (N-n+1) slices (if you don't believe it, try it by hand
with a simple example). But the result of the plugin is a stack of (N-n)
slices.

Moreover, testing the plugin on a simple stack with 4 slices with
alternating uniform intensities:
Source: (n1=255, n2=0, n3=255, n4=0)
The result of the running average with n=2 and the "Average Intensity"
projection is a stack with 2 slices:
Running Z Projector (n=2): (n1a=127, n2a=170)
I have no idea why the average stack has only two slices, and how the value
of the second slice is calculated, I would expect an average stack with
three slices:
(n1a=127, n2a= 127,n3a= 127)

If you specify n=1 (trivial case of averaging) on the same source stack the
result is:
Running Z Projector (n=1): (n1a=255, n2a=127, n3a=127) instead of leaving
the source stack untouched.

I can't find an explaination to this behavior. Is there a bug in this plugin
or am I misunderstanding something ?


Thank you for your help,

Christophe Leterrier
Postdoc

INSERM UMR641 Neurobiology of ionic channels (Michael Seagar)
Ionic channels and neuronal polarity team (Bénédicte Dargent)
IFR Jean Roche - Mediterranee University
51, bd Pierre Dramard 13916 Marseille cedex 20 France
http://ifrjr.nord.univ-mrs.fr/-Institut-Jean-Roche-?lang=en

tel: [phone]
fax: [phone]
email: [hidden email]