Dear mrtrix experts,
I want to achieve an affine (including rigid) and nonlinear transformation, but have some questions:
- What is the difference between
Intuitively I would think the ‘affine’ part already covers rigid transformations. Is there a special reason why ‘rigid’ should be added explicitly besides affine, i.e. does it perform better?
Also, I’m confused about the output options:
- Suppose I choose the registration type
-type rigid_affine_nonlinear, should I then define both rigid and affine outputs e.g.
-rigid rigid.txt -affine affine.txt, or is it sufficient to put
-affine rigid_affine.txtin the assumption that ‘rigid_affine.txt’ would then be the full affine transform (containing rigid transformation as well).
And if I would put
-rigid rigid.txt -affine affine.txtinstead, would that mean that
affine.txtcontains also the rigid transformations (i.e. equal to rigid_affine.txt in my previous example), or only the scaling and skewing, not covered by