[Insight-users] How to create a set of spatially distributed images

[Julien Jomier]

Ali,

You need to put the GaussianType::New() inside the loop so that a new 
GaussianObject is created and added to the group at every iteration.

The itkSpatialObjectToImageFilter is meant to be very generic and 
therefore might be slow for this kind of computation. We might want to 
create a new filter specific to the GaussianSpatialObject. If you want 
to give it a try, go for it, otherwise let me know (I might be able to 
work on it only after tomorrow though).

Julien

Ali - wrote:
> Julien,.
> 
> Thanks, that does the job! However, if we want to add more than one 
> gaussian object by
> adding them to a group, the group only points to one instance of a 
> gaussian object:
>  
> typedef itk::GaussianSpatialObject< 2 > GaussianType;
> typedef itk::GroupSpatialObject< 2 > GroupSpatialObjectType;
> GroupSpatialObjectType::Pointer group = GroupSpatialObjectType::New();
> for(unsigned int i = 0; i < 10; i++)
> {
> gaussianObject->GetObjectToParentTransform()->SetOffset(i * 30);
> gaussianObject->ComputeObjectToWorldTransform();
>  
> group->AddSpatialObject(gaussianObject);
> }
>  
> The above code can generate only 1 gaussian object. How is it possible 
> to add a new
> one to the group where each of them  have different properties? By the 
> way, the use of
> this algorithms seems to be sort of slow, it takes about a second or two 
> per gaussian
> object for a 512 x 512 image -- is it normal?
> 
> 
> 
>  > Ali,
>  >
>  > If you are creating a 2D image, you have to make the dimension of the
>  > GaussianSpatialObject of dimension 2:
>  >
>  > typedef itk::GaussianSpatialObject< 2 > GaussianType;
>  >
>  > This should solve your problem with the corrupted size.
>  >
>  > Also, if you want to put your gaussian at a specific location (in world
>  > coordinate). Let's say at (100,100)mm. You can do something like:
>  >
>  > gaussianObject->GetObjectToParentTransform()->SetOffsetComponent(100);
>  > gaussianObject->ComputeObjectToWorldTransform();
>  >
>  > Hope that helps,
>  >
>  > Julien
>  >
>  > Ali - wrote:
>  > > Gaetan,
>  > >
>  > > I have tried SpatialObjectToImageFilter as explained in the ITK 
> software guide ending up with this error:
>  > >
>  > > stack around the variable 'size' was corrupted.
>  > >
>  > > I use visual studio 8 under xp. I have already set the size for the 
> filter. Here is the code (you can get rid of the VTK part if you dont 
> want to see the result):
>  > >
>  > > ----------------------------------------------------------
>  > >
>  > > #if defined(_MSC_VER)
>  > > #pragma warning ( disable : 4786 )
>  > > #endif
>  > >
>  > > #include "itkImage.h"
>  > > #include "itkGaussianSpatialObject.h"
>  > > #include "itkGroupSpatialObject.h"
>  > > #include "itkSpatialObjectToImageFilter.h"
>  > >
>  > > #include "itkImageToVTKImageFilter.h"
>  > > #include "vtkImageViewer.h"
>  > > #include "vtkRenderWindowInteractor.h"
>  > >
>  > > int main(int, char *[])
>  > > {
>  > > const unsigned int ParticleImageCount = 1;
>  > >
>  > > typedef unsigned char PixelType;
>  > > const unsigned int Dimension = 2;
>  > >
>  > > typedef itk::Image< PixelType, Dimension > ImageType;
>  > > typedef itk::GaussianSpatialObject< 3 > GaussianType;
>  > > typedef itk::SpatialObjectToImageFilter< GaussianType, ImageType > 
> SpatialObjectToImageFilterType;
>  > >
>  > > GaussianType::Pointer gaussianObject = GaussianType::New();
>  > > gaussianObject->SetMaximum(2);
>  > > gaussianObject->SetRadius(5);
>  > >
>  > > ImageType::SizeType size;
>  > > size[0] = 200;
>  > > size[1] = 200;
>  > > SpatialObjectToImageFilterType::Pointer imageFilter = 
> SpatialObjectToImageFilterType::New();
>  > > imageFilter->SetSize(size);
>  > >
>  > > imageFilter->SetInput(gaussianObject);
>  > > imageFilter->Update();
>  > >
>  > > ImageType::Pointer pImage = imageFilter->GetOutput();
>  > >
>  > > typedef itk::ImageToVTKImageFilter<ImageType> ConnectorType;
>  > > ConnectorType::Pointer connector = ConnectorType::New();
>  > > connector->SetInput( pImage );
>  > > vtkImageViewer* viewer = vtkImageViewer::New();
>  > > vtkRenderWindowInteractor* renderWindowInteractor = 
> vtkRenderWindowInteractor::New();
>  > > viewer->SetupInteractor( renderWindowInteractor);
>  > > viewer->SetInput( connector->GetOutput() );
>  > > viewer->Render();
>  > > viewer->SetColorWindow( 255);
>  > > viewer->SetColorLevel( 128);
>  > > renderWindowInteractor->Start();
>  > >
>  > > return 0;
>  > > }
>  > >
>  > >
>  > > _________________________________________________________________
>  > > Be one of the first to try Windows Live Mail.
>  > > 
> http://ideas.live.com/programpage.aspx?versionId=5d21c51a-b161-4314-9b0e-4911fb2b2e6d_______________________________________________
>  > > Insight-users mailing list
>  > > Insight-users at itk.org
>  > > http://www.itk.org/mailman/listinfo/insight-users
>  > >
>  >
> 
> 
> ------------------------------------------------------------------------
> Be one of the first to try Windows Live Mail. 
> <http://ideas.live.com/programpage.aspx?versionId=5d21c51a-b161-4314-9b0e-4911fb2b2e6d>