You will have to choose some threshold, above which you accept those voxels to be gray matter. Then you can use imcalc to do the thresholding, I think something like the following would work:
i1 .* i1 > 0.7
(but I don't remember the exact format of the imcalc equation)
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From: SPM (Statistical Parametric Mapping) [[log in to unmask]] on behalf of Priya Aggarwal [[log in to unmask]]
Sent: Saturday, December 5, 2015 07:53
To: [log in to unmask]
Subject: [SPM] Segmentation in SPM
Hi,
I want to select only grey matter voxels from fMRI images. Segmentation in SPM produces gray matter masks (name starting with c1). However, this mask has so many intensity values apart from 0 and 1.
Ideally it should have only two values (1 and 0). Which intensity values should i use to mask fMRI images?
Many thanks in advance!
with regards,
Priya
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