[Insight-users] Re: ask for help on DeformableMesh3DFilter

[Ting Chen]

Hi! all, sorry for replying late. I will work on to add an default stiff
matrix to both examples.

and plus, please try larger time steps, the current time step in these 2
example are too small for you to notice any major surface deformation

ting

----- Original Message ----- 
From: "Yan Pingkun" <engp1734 at nus.edu.sg>
To: "Samuel Rodríguez Bescos" <srodrigu at gbt.tfo.upm.es>; "Luis Ibanez"
<luis.ibanez at kitware.com>; "Deliang Ye" <dye at jhu.edu>
Cc: <Insight-users at itk.org>
Sent: Monday, April 12, 2004 6:46 AM
Subject: RE: [Insight-users] Re: ask for help on DeformableMesh3DFilter


> Hi, Sam,
>
> I experienced the same problem on this filter. I also noticed that you
would get the same result no matter you set the iteration as 1 or 100. I
found the problem is caused by the uninitialized stiffness matrix m_K[] in
the source code. I discussed this problem with the author Ting Chen.
Actually this is not a bug. The stiffness matrix should be decided by the
user and there's no default value. You need to call "SetStiffnessMatrix" to
set it. Otherwise, the filter can't work properly.
>
> Unfortunately, the current two examples didn't set the matrix. Hence, if
you follow them, you can only get what is very similar to your
initialization.
>
> HTH,
> Pingkun
>
> -----Original Message-----
> From: insight-users-admin at itk.org [mailto:insight-users-admin at itk.org] On
Behalf Of Samuel Rodríguez Bescos
> Sent: Monday, April 12, 2004 5:20 PM
> To: Luis Ibanez; Deliang Ye
> Cc: Insight-users at itk.org
> Subject: [Insight-users] Re: ask for help on DeformableMesh3DFilter
>
>
> Hi, Deliang,
>
> I agree with Luis. In adition, I noticed that the surface didn't have
> important changes in its evolution when I used   the
DeformableMesh3DFilter
> in an example similiar to yours (to refine a surface model got from a
region growing  method) . I didn't try any level sets method but I think
that they could be better option.
>
> With reference to the question about de values of the parameters of the
filter I think that there aren't a fixed rules, unfortunately we have to
test and check.
>
> Regards,
>
> Sam
>
> ============================================
> Samuel Rodríguez Bescós
> Bioengineering and Telemedicine Department
> ETSI Telecomunicacion
>
> Universidad Politécnica de Madrid
> Ciudad Universitaria s/n - 28040 Madrid - Spain
>
> Ph: +34 91 550 04 35 (ext.32) // +34 91 549 57 00 (ext. 332)
> Fax: +34 91 336 68 38
>
> Email: srodrigu at gbt.tfo.upm.es
> Web: http://www.gbt.tfo.upm.es
============================================
>
>
> ----- Original Message ----- 
> From: "Luis Ibanez" <luis.ibanez at kitware.com>
> To: "Deliang Ye" <dye at jhu.edu>
> Cc: <srodrigu at gbt.tfo.upm.es>; <Insight-users at itk.org>
> Sent: Wednesday, April 07, 2004 8:40 PM
> Subject: Re: ask for help on DeformableMesh3DFilter
>
>
> >
> > Hi Deliang,
> >
> > The DeformableModel filter is quite unstable
> > and may not be the best options for refining
> > an existing segmentation.
> >
> > You may want to look at the LevelSet methods
> > since they provide better mechanisms for
> > enforcing estability.
> >
> > Please take a look at the LevelSet chapter
> > in the software guide.
> >
> >   http://www.itk.org/ItkSoftwareGuide.pdf
> >
> > Section 9.3, pdf-page 363.
> > In particular you may want to look at
> >
> >   - GeodesicActiveContours
> >   - ThresholdLevelSet
> >   - CannyEdgesLevelSet
> >
> > Associated examples are available under
> >
> >    Insight/Examples/Segmentation
> >
> >
> >
> >
> > Regards,
> >
> >
> >    Luis
> >
> >
> > ----------------
> > Deliang Ye wrote:
> >
> > > Hi, Luis and Sam,
> > >
> > > I got a rough segmentation of rat spinal cord by region growing, I
> > > would like to use deformable mesh filter to refine the result. But
> > > the program failed, and told me memory access violation. I have not
> > > changed any parameters in DeformableModel1.cxx  in ITK, what is the
> > > rule of thumb to
> set
> > > the parameters, such as stiffness, scale, gradient magnitude, time
> > > step,
> and
> > > step threshold in DeformableMesh3DFilter?
> > >
> > > Please check that attached file,
> > >
> > > Appreciate you for help!
> > >
> > > --Deliang Ye
> > >
> > >
> > > --------------------------------------------------------------------
> > > ----
> > >
> >
> >
> >
>
>
>
>
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