[Insight-users] Principal Axes pre-registration

[Oscar Esteban Sanz-Dranguet]

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