Hi Rachel,
For evaluating the sform code, you can use nifti_tool
to display the entire header, or maybe just the sform
code. Consider these 2 examples:
nifti_tool -disp_hdr -infiles zstat.nii.gz
nifti_tool -disp_hdr -field sform_code -infiles zstat.nii.gz
If you are using one software package to write the
NIfTI datasets, and it wrote some with a proper sform
code, that suggests that maybe your +orig dataset was
not actually in a standard space. I can only guess on
that.
The "Where am I" output is based on Talairach coordinates.
It will output coordinates in MNI space, too, but that
still assumes the dataset is in Talairach space. I would
need to investigate what happens with a dataset that has an
sform code for MNI space. I suggest you ask about that in
a separate thread.
Note that there is no transformation applied when the data
is read. It is simply assumed to be in some space.
- rick