Dear Eric,
your formula looks ok. You should check your threshold - you could do this
eg. in CheckReg by using "Image->Window->local->manual" and setting
min/max to [threshold threshold+eps]. This will display your image
"binarised", with below-threshold voxels black.
Volkmar
On Tue, 3 Jul 2007, Eric Schumacher wrote:
> Hello,
>
> I'm trying to use the Image Calculator built into SPM 5 to mask voxels below
> a certain threshold. As recommended in the SPM 5 manual, I used the ImCalc
> to create a binary mask of the image (i1>threshold) and multiplied that times
> the original image ( i1.*(i1>threshold)). Insignificant voxels should get
> multiplied by 0 in this case, but when I view the resulting, masked image in
> software like mricro, all the below threshold voxels are still present. Has
> anyone had a similar problem? Am I using the calculator incorrectly?
>
> Thanks in advance for your help?
>
>
> -eric
>
> Eric H. Schumacher, Ph.D.
> School of Psychology
> Georgia Institute of Technology
> 654 Cherry Street
> Atlanta, GA 30332-0170
> phone: 404-894-6067
> lab: 404-385-7056
> fax: 404-894-8905
> email: [log in to unmask]
> website: www.psychology.gatech.edu/CoNTRoL
--
Volkmar Glauche
-
Department of Neurology [log in to unmask]
Universitaetsklinikum Freiburg Phone 49(0)761-270-5331
Breisacher Str. 64 Fax 49(0)761-270-5416
79106 Freiburg http://fbi.uniklinik-freiburg.de/
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