[Insight-users] Question about generating and composing deformation fields

[Anja Ende]

Hello everyone,

I have a series of affine and non-rigid transformations and what I
would like to do is create one single deformation field by combining
these deformations and then use this final deformation field to
resample my image.

So I need to do two different compositions (I am not sure if I should
compose or add these deformation fields. The formulation of
composition is not completely clear to me as well).

1: I have an affine transformation and a non-rigid transformation. So,
given an initial image, how can I create a deformation field that
encapsulates these two transformations.
2: I have a non-rigid transformation followed by an affine
transformation. Again, I would like to create a deformation field that
encapsulates them.

I would be very grateful if anyone could point out how I might achieve
this in ITK. Also, maybe more experienced people doing medical image
registration could share some information on how deformation foelds
are combined (addition vs composition)

Many thanks for any help you can give me,

Anja