Note that by default, the template is assumed to be smoothed by 8mm. In order
to match another image to the template, SPM will therefore smooth this other
image by 8mm => giving you an affine transform that is not the identity.
Try changing from
defaults.normalise.estimate.smosrc = 8;
defaults.normalise.estimate.smoref = 0;
to
defaults.normalise.estimate.smosrc = 8;
defaults.normalise.estimate.smoref = 8;
As an aside, if you are normalising an image to some other image that is not
an SPM template, then (I think) you can change the voxel sizes to [NaN NaN
NaN], and the bounding box to ones(2,3)*NaN , and it will write out the
images with the appropriate dimensions.
Best regards,
-John
> if I normalize an image B_0 (B_0 source image and image to write) with
> an affine transformation to itself (B_0 template), I obtain another
> image than before:
> wB_0 =! B_0
> Does anybody know why?
>
> The defaults are modified in the following sence:
>
> defaults.normalise.write.vox = [0.89 0.89 3.6];
> defaults.normalise.write.bb = [-113 -113 -62; 114 114 63];
>
> and only an affine transformation is allowed. Everything else is not
> changed.
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