If you are referring to Segmenting in SPM5, then the interpolation involves
smoothing the data slightly (to reduce aliasing effects) and using trilinear
interpolation. Simple application of other interpolation approaches would
result in negative values being introduced, which may not be desirable.
If you want to have 1x1x1mm spatially normalised images, then you could use
the Segment button to write the data in native space, and then use the
Normalise button (with the seg_sn.mat file generated by the Segmentation) to
write a spatially normalised version.
best regards,
-John
On Monday 01 October 2007 16:17, West, John D. wrote:
> Hello.
>
>
>
> I have a couple of quick questions on VBM Preprocessing.
>
>
>
> 1. What is the interpolation used when the data is normalized? I
> know the voxel size is 2x2x2, but I am not sure what the interpolation
> used is. Is there a recommended interpolation if I wanted to change it?
>
> 2. We would like to write out to 1x1x1 voxel size. Is the best
> way to do this to just resample the tpm images to 1x1x1?
>
>
>
> Thanks for your help.
>
> -John West
>
> Imaging Analyst
>
> IU School of Medicine
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