Thanks, Steve. Hope Ged can hear us.
Cheers
On Monday 21 January 2008 18:52:46 Steve Smith wrote:
> I think Ged has a solution to this for IRTK <-> FLIRT?
> Cheers.
>
> On 21 Jan 2008, at 09:44, Martin Kavec wrote:
> > Hi,
> >
> > I'm trying to convert FSL's 4x4 transform to the IRTK's affine
> > transform. I
> > have been experimenting on this for quite a while and can not get
> > through it.
> >
> > The main difference is that IRTK dof transform has the origin of the
> > rotation
> > in the center of the image, while FSL has it in the 0,0,0. So the
> > rotation in
> > mat causes a translation, which needs to be accounted for in the dof
> > matrix.
> >
> > I decompose translations, rotations, scalings, and skews from from
> > the mat
> > file and using these I compose the dof transformation. Rotations,
> > scalings,
> > and skews are simple to get, but since the origins of the mat
> > transform is in
> > 0,0,0, the transformation includes rotation-related translations as
> > well, and
> > this is the major problem I have.
> >
> > So my questions are:
> >
> > 1. If I have existing FSL affine transform, which maps input image to
> > reference using FLIRT, how can I compose an equivalent affine
> > transform with
> > the origin of rotation in the center of the image and,
> >
> > 2. if I finally have the transform, and I use avscale to decompose
> > it to
> > rotations, scales, skews, and translations, if the translations will
> > be
> > affected by the rotations?
> >
> > Thanks a lot for ideas in advance.
> >
> > Martin
>
> ---------------------------------------------------------------------------
> Stephen M. Smith, Professor of Biomedical Engineering
> Associate Director, Oxford University FMRIB Centre
>
> FMRIB, JR Hospital, Headington, Oxford OX3 9DU, UK
> +44 (0) 1865 222726 (fax 222717)
> [log in to unmask] http://www.fmrib.ox.ac.uk/~steve
> ---------------------------------------------------------------------------
|