[Insight-users] VTK - ITK - VTK Pipeline problems

[Jesse C Cronce]

For the mailing list archives -

For what I am trying to do, I need several copies of the same images so
that I can do different filtering on the different versions, and then do
statistical comparison later. To do this what I ended up doing was

ImageType::Pointer array[7]
ImageType::Pointer array2[7] ... etc

Then, after doing each pass of computation use an 

itk::ImageDuplicator< type >

and do 

duplicator->SetInputImage( filter->GetOutput() )
duplicator->Update()
array[ whatever ] = duplicator->GetOutput();
array[ whatever ]->DisconnectPipeline()

So far this does not crash, and the images all appear to be correct (at
least for now). I think that this will bleed memory, but for right now
it's not an issue, and if it does I will fix that problem later. 

A big thanks to Karthik for getting me started on the right path.
Hopefully this post will help someone else one day.

JCC

On Mon, 2005-10-31 at 15:47 -0500, Jesse C Cronce wrote:
> Sorry, what I mean is ImageType::Pointer x[20];
> On Mon, 2005-10-31 at 14:31 -0500, Jesse C Cronce wrote:
> > Is it possible to have ImageType *x[20];
> > 
> > So that you can disconnect a particular image, make a few parameter
> > changes to the filter, call it's upadate method again, and disconnect
> > the next image w/out overwriting the memory of the initial image ?
> > 
> > Thanks,
> > JCC
> > 
> > On Mon, 2005-10-31 at 13:53 -0500, Karthik Krishnan wrote:
> > > Jesse C Cronce wrote:
> > > 
> > > >If you do a DisconnectPipeline, that will also disconnect memory
> > > >management of the image from the ITK libraries as well, right ? 
> > > >
> > > Not if you use smart pointers. (Memory management should be taken care 
> > > of) For instance, this is ok if you had
> > > 
> > > filter->Update();
> > > ImageType::Pointer x = filter->GetOutput();
> > > x->DisconnectPipeline();
> > > 
> > > this is not ok.
> > > 
> > > filter->Update();
> > > ImageType* x = filter->GetOutput();
> > > x->DisconnectPipeline();
> > > 
> > > The reference count is needed to prevent x from getting destroyed.
> > > 
> > > >(meaning
> > > >that the memory will have to be deleted/freed when no longer in use)
> > > >Also, if you call a GetOutput() on the filter that has been disconnected
> > > >from the pipeline, it looks like the result should be a NULL pointer
> > > >(from the code itkDataObject.cxx - 
> > > >
> > > >    m_Source->SetNthOutput(m_SourceOutputIndex, 0);
> > > >
> > > >) is this also correct ?
> > > >
> > > >  
> > > >
> > > yes
> > > 
> > > >Thanks!
> > > >JCC
> > > >
> > > >On Mon, 2005-10-31 at 10:53 -0500, Karthik Krishnan wrote:
> > > >  
> > > >
> > > >>Did you try to disconnect the objects from teh pipeline ?
> > > >>
> > > >>In ITK:
> > > >>
> > > >>filter->Update();
> > > >>itkImage = filter->GetOutput();
> > > >>itkImage->DisconnectPipeline();
> > > >>
> > > >>In VTK:
> > > >>
> > > >>use UnRegisterAllOutputs() to disconnect the pipeline
> > > >>or use ShallowCopy
> > > >>
> > > >>
> > > >>
> > > >>Istvan Matis wrote:
> > > >>
> > > >>    
> > > >>
> > > >>>Hello ITK users,
> > > >>> 
> > > >>>I am using a complex pipeline to convert vtkImageData to itk Image, 
> > > >>>apply some filters on it (each time a different filter) like 
> > > >>>smoohting, segmentation, then convert back to VTK in order to 
> > > >>>visualize it.
> > > >>>My problem is that I receive various errors, "unhandled exceptions" 
> > > >>>sometimes in the itk sources sometimes in system dlls, usually when I 
> > > >>>want to apply the itk filters for the 2nd time.
> > > >>> 
> > > >>>I am using the same pipeline several times on several (different) 
> > > >>>images read into VTK.
> > > >>>As I understood, if one element (object) in the VTK->ITK->VTK pipeline 
> > > >>>is destroyed the whole pipeline will crash. In order to prevent this I 
> > > >>>use vtkImageCast to "Clone" the final vtk output in order to separate 
> > > >>>the output vtkImageData from the whole pipeline.
> > > >>> 
> > > >>>Here is the sketch of the pipeline:
> > > >>> 
> > > >>>vtkImageData Input ->
> > > >>>-> vtkImageCast ->
> > > >>>-> vtkImageData Input 2 ->
> > > >>>-> itk::VTKImageToImageFilter ->
> > > >>>-> itk::Image ->
> > > >>>-> " different itk filter each time: ex: 
> > > >>>itk::ConnectedThresholdImageFilter or itk::CurvatureFlowImageFilter " ->
> > > >>>-> itk::Image Output ->
> > > >>>-> itk::ImageToVTKImageFilter ->
> > > >>>-> vtkImageData Output ->
> > > >>>-> vtkImageCast ->
> > > >>>-> vtkImageData Output 2
> > > >>> 
> > > >>>I use ->Update() at every step!
> > > >>> 
> > > >>>By the way I am using itk 2-0-0, vtk 4-4, VC++6 with SP6, WinXP Pro.
> > > >>> 
> > > >>>Is a solution to recreate (Delete() and New()) all the itk and vtk 
> > > >>>filters in the pipeline each time they need to be used? I observed 
> > > >>>that if I destroy even one of these filters the whole thing crashes, 
> > > >>>and not immediately, but sooner or later, somewhere when vtk needs the 
> > > >>>data.
> > > >>> 
> > > >>>My question is:
> > > >>>How can I separate the resulting vtkImage from the whole vtk-itk-vtk 
> > > >>>pipeline once it was processed?
> > > >>>Or more generally:
> > > >>>How can I reuse the whole pipeline on different images with different 
> > > >>>sizes and attributes?
> > > >>> 
> > > >>>Any hints will be gratefully apreciated.
> > > >>> 
> > > >>>Sincerelly,
> > > >>>Istvan
> > > >>> 
> > > >>> 
> > > >>>
> > > >>>------------------------------------------------------------------------
> > > >>>
> > > >>>_______________________________________________
> > > >>>Insight-users mailing list
> > > >>>Insight-users at itk.org
> > > >>>http://www.itk.org/mailman/listinfo/insight-users
> > > >>> 
> > > >>>
> > > >>>      
> > > >>>
> > > >>_______________________________________________
> > > >>Insight-users mailing list
> > > >>Insight-users at itk.org
> > > >>http://www.itk.org/mailman/listinfo/insight-users
> > > >>    
> > > >>
> > > >
> > > >
> > > >  
> > > >
> > 
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