[Insight-users] some contributions
Mathieu De Craene
decraene at tele.ucl.ac.be
Fri Mar 18 04:04:23 EST 2005
Le jeudi 17 mars 2005 à 09:10 -0500, Blezek, Daniel J (Research) a
écrit :
> Stefan, Marius, Mathieu,
>
> Excellent. I liked the try / catch blocks, and the stopping
> criteria in Mathieu's implementation. Essentially, the code is the
> same across all 3 implementations... As you would expect from the
> nicely written paper.
>
> - what should be the default values for a, A, C?
> - I used a=A=c=0.1 (Don't trust my implementation...)
> - Mathieu uses a=01.6, A = 60(!), C=0.01
In fact, this value should be changed to 0.5 or 1. I used a Set() method
in the main code to change the default value. For rigid registration for
instance, I doubt you will measure anything by changing the translations
coefficients by 0.01 mm ;-)
If the A coefficient is big, it means that the optimizer will make big
steps at the initial iterations.
An idea of the successive trials made by the spsa optimizer in rigid
registration can be seen on this animation :
http://www.tele.ucl.ac.be/~decraene/anims/RIGID.mpeg
I think it is good to keep this parameter big enough if we want to keep
the robust behavior of this optimizer.
> - Stefan uses a=A=c=1.0
> - Are we OK with Alpha = 0.602, Gamma = 0.101?
>
I have never experimented other set of values but these work fine for
me !
>
> -dan
> -----Original Message-----
> From: Stefan Klein [mailto:stefan at isi.uu.nl]
> Sent: Thursday, March 17, 2005 8:55 AM
> To: Blezek, Daniel J (Research); Mathieu De Craene
> Cc: Insight-users at itk.org; insight-developers at itk.org
> Subject: RE: [Insight-users] some contributions
>
>
> Eh, but then we'll have 2 SPSA-optimizers....
> Wouldn't it be the best to have one that combines the good of
> all 3 versions?
>
> plan:
> - we include the scales thing and the test and some elements
> from Mathieu's implementation
> - we'll mail it to the list.
> - you check it (if we combined all features correctly) and
> correct it
> - Daniel commits it to the itk.
>
> Marius&Stefan.
>
>
>
> At 08:39 17/03/05, Blezek, Daniel J (Research) wrote:
> > Oddly enough, I also have an implementation of the SPSA
> > algorithm! I offered to put Stefan's implementation in,
> > provided he account for m_Scale and write a test. I'll make
> > the same offer for you, Mathieu. I've put my code on the
> > itk Wiki @ http://itk.org/Wiki/SPSAOptimizer however, I
> > haven't tested my code very well, as it's new.
> >
> > -dan
> >
> > -----Original Message-----
> > From: insight-users-bounces at itk.org
> > [mailto:insight-users-bounces at itk.org]On Behalf Of Mathieu
> > De Craene
> > Sent: Thursday, March 17, 2005 8:20 AM
> > To: Stefan Klein
> > Cc: Insight-users at itk.org; insight-developers at itk.org
> > Subject: Re: [Insight-users] some contributions
> >
> >
> > Le mercredi 16 mars 2005 à 21:34 +0100, Stefan Klein a
> > écrit :
> > > Hi all,
> > >
> > > We have created some classes that are useful for us. We
> > hope also for other
> > > people, so we would like to contribute them. The code can
> > be found for
> > > download on:
> > > http://www.isi.uu.nl/People/Stefan/
> > >
> > > - itkEulerTransform.h: This class is a wrap around the
> > Euler2DTransform and
> > > the Euler3DTransform. In this way it is templated over the
> > dimension, like
> > > other Transform-classes.
> > >
> > > - SimultaneousPerturbation.zip: This class implements the
> > so-called
> > > Simultaneous Perturbation method as an ITK optimizer. For
> > more info on this
> > > optimization method, go to:
> > > http://www.jhuapl.edu/SPSA
> > >
> >
> > I have also have some code for SPSA optimization. I found it
> > quite
> > useful for rigid registration (it seems to be pretty
> > robust). The source
> > code for a rigid registration application based on ITK is
> > available on
> >
> > http://euterpe.tele.ucl.ac.be/Waleo2/vesale/
> >
> > I would like to compare our implementations of this
> > optimizer.
> >
> > Regards,
> >
> > Mathieu.
> >
> > > - FullSearch.zip: This class implements a (semi-)Full
> > Search optimization
> > > routine. This can be useful for research, to scan the
> > optimization surface,
> > > or to evaluate the result of other optimizers. It allows
> > the user to
> > > specify which parameters should be evaluated, in which
> > range.
> > >
> > > Since we have contributed 3 things now, we also have a
> > feature request; as
> > > a reward :-)
> > >
> > > Would it be possible to add a public function to the
> > > MattesMutualInformationImageToImageMetric that forces the
> > metric to select
> > > new spatial samples? This would be useful if you would
> > want new spatial
> > > samples every iteration for example.
> > >
> > > We hope that the contributions are useful. Any comments
> > are welcome!!
> > >
> > > Marius and Stefan.
> > >
> > >
> > > Marius Staring, Stefan Klein
> > > Image Sciences Institute
> > > University Medical Centre Utrecht
> > > Heidelberglaan 100, 3584 CX Utrecht, The Netherlands
> > > phone: +31 (0)30 250 3186, fax: +31 (0)30 251 3399
> > > {marius,stefan}@isi.uu.nl,
> > > http://www.isi.uu.nl/People/Marius
> > > http://www.isi.uu.nl/People/?stefan
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > _______________________________________________
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> > > Insight-users at itk.org
> > > http://www.itk.org/mailman/listinfo/insight-users
> > >
> >
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>
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