[Insight-users] pipeline type conversion problem

[Christos Panagiotou]

Dear luis

I am trying to get an affine transform optimized.. (using the 
MultiResMIRegistration applicaiton)
however in some tests i ve run i am getting very noisy plots of 
iterations-metric values.
I thought it would be better to try a simpler example.

I have created a white cube (just the surface - not filled) in a black 
background.
I ve also created a similar parallelogram.

I know that these two shapes are not multi-modal however i thought that 
a mutual information metric with
a gradient descent optimizer would be able to tackle this.

I cannot get any close to this registration test. Would you think that 
maybe the fact that the shapes are normalized
before the registration would affect the result? (as they are of 
identical modality)

Well i am trying to disable the normalizer but i ve got a problem with 
the pipeline

in MultiResMIRegistration -> MIMPreprocessor.txx you have the following 
lines of code

  typename CentererType::Pointer   centerer;
  typename NormalizerType::Pointer normalizer;
  typename PermuterType::Pointer   permuter;
  typename FlipperType::Pointer    flipper;

  // Process the fixed image
  centerer =  CentererType::New();
  normalizer = NormalizerType::New();

  centerer->CenterImageOn();
  centerer->SetInput( m_InputFixedImage );
 
  normalizer->SetInput( centerer->GetOutput() );
  normalizer->Update();
  m_OutputFixedImage = normalizer->GetOutput();

m_OutputFixedImage of course is of different type than the m_InputFixedImage

how would be possible to get something like the following:
m_OutputFixedImage = centerer->GetOutput();

from what i ve understood centerer returns a m_InputFixedImage type, so 
how could i convert this to m_OutputFixedImage?
i ve tried to use RescaleIntensityImageFilter however i could not make 
it work...

i think m_InputFixedImage type is <sighned short, 3> and 
m_OutputFixedImage type is <float,3>

thanks
christos




-- 
---------------------------------------------------

 Christos Panagiotou

 PhD student
 University College London
 Dept. of Computer Science

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