[Insight-users] about MIThinPlateSplineRegistrator

[zhangzhijun]

hi Luis:

         I am wondering whether choosing of source landmark as parameters
will be ok,
the mutual information implemented in ITK using the stochastic gradient
descent to find
the optimal. The entropy and the joint entropy are estimated by using 2
groups of sampling
points and for each iteration the sampling points in source and target image
are chozen arbitrarily
and are not same, so How could the target landmark be fixed and the source
landmark
be adjusted?

regards,
zhang zhijun


----- Original Message -----
From: "Luis Ibanez" <luis.ibanez@kitware.com>
To: "zhangzhijun" <zjzhang@ee.cuhk.edu.hk>
Cc: <insight-users@public.kitware.com>
Sent: Saturday, July 13, 2002 11:16 AM
Subject: Re: [Insight-users] about MIThinPlateSplineRegistrator


>
> Hi Zhang,
>
> The Set/Get Parameters methods have been
> added to the itkKernelTransform class.
>
> Please do a cvs update in order to get these
> modifications.
>
> The parameters are simply the sequence of
> coordinates components of the landmarks on
> the source space.
>
> A registration method will require (as you
> said) to initialize the transform by providing
> initial sets of landmarks in the source space
> and the target space.  Then, only the landmarks
> in the source space will be adjusted in order
> to obtain a transform that optimizes the matching
> between the fixed and moving images.
>
> The choice of using the Source landmarks components
> as parameters is a bit arbitrary. It could have been
> the Target landmarks, or even both.  Those options
> may be mathematically equivalent but they will
> probably result in performance differences during
> the exploration of the parameter space made by the
> optimizer.
>
>
> Please let us know if you encounter any problem
> with these changes.
>
>
> Thanks
>
> Luis
>
>
> ===============================================
>
> zhangzhijun wrote:
>
> > Dear Luis:
> >          I want to put the TPS, EBS and VS transformation into the
> > multi-modal registration frame work
> > it is implemented following the 3 steps--- transform, similarity metric
and
> > optimization, now since the
> > example of MIThinplatesplineRegistrator is not complete, I think I need
do
> > the following work:
> >  1. Add an Initialization of the parameters for the TPS, in my case I
want
> > to register two
> > 2D image of 181*217 dimensions, I choose totally 10*11 landmarks for
> > calculating of the TPS parameters,
> > After I calculate the W matrix, the itkKernelTransformation reorgnized
the
> > Wmatrix into three part but the
> > 3 matrix members are all protected member, I find I can't have access to
it.
> > I want to set the 226 parameters
> > and then use optimization method to do the optimization.
> >  2  also I don't know how the deviation in the itk is implemented and
what's
> > the order for these 226 parameters.
> > because I need do an steepest descent optimization, so the order of
every
> > parameter should follow some convention,
> > I don't know what is it.
> >
> > regards,
> > zhang zhijun
> >
> > _______________________________________________
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> > http://public.kitware.com/mailman/listinfo/insight-users
> >
> >
>
>
>
>
>