Mark/Steve
thanks for insight into the FLIRT implementation. I can understant it better
now.
I have one practical comment. I very much appreciate the collection of
lectures you have on the FSL web-page. However, I was not aware of it until
Christian put it into my attention in reply to this thread. I didn't think of
looking for it in FAQ. What would you think of placing a "Documentation" link
on the web-page which would point also to the lectures.
Cheers.
Martin
On Saturday 04 December 2004 10:45, Mark Jenkinson wrote:
> Hi,
>
> Steve is right - the 7th DOF is a global scaling.
>
> I also wanted to add that quaternions do not specify
> what kind of transformation you are applying - they are
> a way of representing angles, much in the same way as
> Euler angles are. Hence you need to know more about
> what they mean in ITK by a "Quaternian3DTransform".
> If you hadn't said, I would have assumed that this would
> be a rigid-body transformation as it is a standard
> convention to use quaternions to represent rotations
> alone, and so this plus translations would give a 6 dof
> rigid-body transformation. My guess is that any 7 dof
> transformation (using quaternions or not) is probably
> the same as ours: rigid-body + global scaling. But you
> should double check this with any available ITK information.
>
> All the best,
> Mark
>
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