[MINC-users] Affine transformation matrix

[Vladimir S. Fonov]

Hello,


I do it in a following way:

assuming that input.xfm is input file and output.xfm will contain final 
result ( scale.xfm and unscale.xfm are temporary files):

param2xmf `xfm2param input.xfm|fgrep -- -scale` scale.xfm
xfminvert scale.xfm unscale.xfm
xfmconcat input.xfm unscale.xfm output.xfm


this way transformation matrix is updated appropriately.

On 11-06-21 08:22 PM, Aaryani Tipirneni wrote:
> Hi all,
>
>   I have a basic question - As we know, If we do affine registration using mritotal to the atlas, we will get a .xfm file with the translations, rotations, scaling and shearing. If I now want to remove the scaling from the .xfm matrix so that the coregistered data has the same scaling as the original data (to avoid stretching and shrinking), do you expect to still coregister well? Do I have to change even the rotations and translations accordingly?
>
> Please advice!
>
> Thanks for your time,
> Aaryani
> _______________________________________________
> MINC-users at bic.mni.mcgill.ca
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-- 
Best regards,
  Vladimir S. Fonov ~ vladimir.fonov <at> gmail.com