[Insight-users] Principal Axes pre-registration

[Luis Ibanez]

Hi Oscar,

What you have mentioned is close enough...


The matrix that you want is actually the Axis of the Moving image
multiplied by the inverse of the Axis of the Fixed image.

You may want to look at the code of the file:

     Insight/Code/Common/itkCenteredVersorTransformInitializer.txx

(attached to this email for your convenience).

Note also, that we just fixed this file in CVS, after looking at your email,
Therefore, if you want to look at the ITK source code version, you should
get an updated CVS checkout.


    Regards,


           Luis


----------------------------------------------------
On Tue, Aug 11, 2009 at 7:56 AM, Oscar Esteban Sanz-Dranguet <
oesteban at die.upm.es> wrote:

> Hi all,
>
> I'm registering RM-SPECT pairs, using centered transforms and moments
> initialization. I would like to improve the initialization not only using
> the centers of masses of the two images. I thought that aligning the
> Principal Axes would work, but I don't understand the implementation as well
> as I need to code it.
>
> I've read the documentation of
> itk::ImageMomentsCalculator<>::GetPrincipalAxes(), but I can't find out how
> to compute the matrix that I should apply to the moving image in order to
> make the correct rotation.
>
> I think that I should calculate the inverse of the principal axes matrix of
> the moving image. Then, multiply it with the principal axes matrix of the
> fixed image. Isn't it?
>
> Thanks in advance. Best Regards.
>
> --
> Oscar Esteban
> BIT - UPM (http://www.die.upm.es/im/)
> +34 913 366 827 ext.4248
>
> _____________________________________
> Powered by www.kitware.com
>
> Visit other Kitware open-source projects at
> http://www.kitware.com/opensource/opensource.html
>
> Please keep messages on-topic and check the ITK FAQ at:
> http://www.itk.org/Wiki/ITK_FAQ
>
> Follow this link to subscribe/unsubscribe:
> http://www.itk.org/mailman/listinfo/insight-users
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.itk.org/pipermail/insight-users/attachments/20090815/cb6bbb69/attachment-0001.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: itkCenteredVersorTransformInitializer.txx
Type: application/octet-stream
Size: 2286 bytes
Desc: not available
URL: <http://www.itk.org/pipermail/insight-users/attachments/20090815/cb6bbb69/attachment-0001.obj>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: itkCenteredVersorTransformInitializer.h
Type: text/x-chdr
Size: 4521 bytes
Desc: not available
URL: <http://www.itk.org/pipermail/insight-users/attachments/20090815/cb6bbb69/attachment-0001.h>