You need the mapping from the individual space to the template space in
order to do this. Normally, writing spatially normalized images
requires the inverse of this mapping (because the procedure involves
scanning through the spatially normalized image, and reading the
appropriate values from the original version - rather than scanning
through the original version and putting the values into the appropriate
location of the spatially normalized image).
The parameterization of this transform is saved in the seg_inv_sn.mat
file. Translating this parameterization into an actual deformation
field can be done via the get_sn2def function that starts at around line
68 of spm_defs.m. Alternatively, you could write out the *_
seg_inv_sn.mat file as a deformation field (using the
. . Parameter File: *_seg_inv_sn.mat
. Save as: filename
This will allow you to read off the values from y_filename.img.
From: SPM (Statistical Parametric Mapping) [mailto:[log in to unmask]]
On Behalf Of Roman Rodionov
Sent: Wednesday, February 21, 2007 12:49 AM
To: [log in to unmask]
Subject: [SPM] applying normalisation parameters to individual voxels
Dear John and others,
I need to translate several points/voxels from individual space (image
before normalisation) into MNI space (image after normalisation).
The question is 'how to apply normalisation parameters which are one of
outputs of the Segmentation (_sn.mat) in order to translate individual
voxels?' Is there SPM function which does that?
Sorry if this question is not for the first time here. I've tried to
analogous question in the list but didn't succeed.