[Insight-users] Questions about the Diffeomorphic Demons Registration

[Luis Ibanez]

Hi Chunfang,

Where did you find the
DiffeomorphicDemonsRegistrationWithMaskFilter  ?


or are you referring to ?
http://www.itk.org/Doxygen/html/classitk_1_1DiffeomorphicDemonsRegistrationFilter.html


The only version that I find with a mask is in

Slicer3/Applications/CLI/
    BRAINSTools/
       BRAINSDemonWarp/
           itkDiffeomorphicDemonsRegistrationWithMaskFilter.h


Is that the one you are using ?

-----

Have you explored different values for

             SetMaximumUpdateStepLength()    ?


--

It would be helpful if you could post a minimal example
of your code to the mailing list.


    Luis


----------------------------------------------------------------
On Thu, May 12, 2011 at 7:06 PM, Chunfang Wang <wchunfang at gmail.com> wrote:
> Hello All,
>
> I have a problem with the Diffeomorphic Demons registration.
> Hope anyone can give me some suggestions.
> Thanks in advance.
>
> I used the DiffeomorphicDemonsRegistrationWithMaskFilter with two level
> resolutions,
> the main parameters of the filter is below :
>
> MaximumRMSError = 0.01;
> MaximalStepLength[ ] = {2, 1};
> DemonsNumOfIterations[ ] =  {6, 10};
> double DemonsElasticSigma [ ] = {0.8, 0.4} ;
> double DemonsViscousSigma[ ] = {0.8, 0.4} ;
>
> I set an observer of the filter to print out the RMS change  in each
> iteration.
> The registration results is quite well if the registration is run
> sucessfully.
> However, the result is not stable. In many cases, the observer print out the
> RMS change is "nan",  and no deformation field is generated.
> The program can run through in this situation, and there is no exception
> error caught .
>
> The normal RMS change of my test images always goes from around 0.3 to 0.1,
> so I think it is not the reason that the value is nonreprentable, which is
> the defination of "nan".
> The same images with the same parameters in the program can obtain sucessful
> registration results sometime, and failed with the RMS changes "nan".
>
> You need to run the program four or five times, and possible the
> registration will be sucessful once  if i am lucky enough.
>
> I don't know what the reason of this unstable problem,  and hope someone can
> figure me out.
>
> Thanks.
>
> Kind regards,
> Chunfang
>
>
>
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