[Insight-users] a question about using itkImageToVTKImageFilter

[LI XIN]

Hello, insight users

I have a question when I use itkImageToVTKImageFilter.

I tried to use itkImageFileReader to read a 3D raw image file, change it to VTK image data using itkImageToVTKImageFilter, and then display one slice of the image using vtkImageViewer. But the slice could not be displayed properly. 

I found that the data spacing are 1 ,1 ,1 and the dimensions are 0 , -1 , 0 after ITK image data changed to VTK image data.

My code is:

                     typedef float     PixelType;
	const   unsigned int   Dimension = 3;

	typedef itk::Image< PixelType, Dimension >   ImageType;
	typedef itk::ImageFileReader< ImageType >    ReaderType;
	typedef itk::RawImageIO<PixelType, Dimension>	ImageIOType;
	typedef itk::ImageToVTKImageFilter< ImageType > ConnectorType;

	ReaderType::Pointer reader = ReaderType::New();
	ImageIOType::Pointer rawIO = ImageIOType::New();
	ConnectorType::Pointer connector = ConnectorType::New();
	
	reader->SetImageIO(rawIO);
	reader->SetFileName( "brain.raw" );

	rawIO->SetFileDimensionality(3);
                     rawIO->SetOrigin(0,0.0);
	rawIO->SetOrigin(1,0.0);
	rawIO->SetOrigin(2,0.0);

	rawIO->SetDimensions(0,256);
	rawIO->SetDimensions(1,256);
	rawIO->SetDimensions(2,50);

	rawIO->SetSpacing(0,0.9609375);
	rawIO->SetSpacing(1,0.9609375);
	rawIO->SetSpacing(2,2.2);

	try
	{
		reader->Update();
	}
	catch (itk::ExceptionObject & err)
	{
		cout << "ExceptionObject caught!" << endl;
		cout << err << endl;
		return -1;
	}
                     
                    connector->SetInput(reader->GetOutput());

                    vtkImageViewer *viewer=vtkImageViewer::New();
	vtkRenderWindowInteractor *iren = vtkRenderWindowInteractor::New();

	viewer->SetInput(connector->GetOutput());

	float max=(((vtkDataSet *)(connector->GetOutput()))->GetScalarRange())[1];

	viewer->SetZSlice(10);
	viewer->SetColorWindow(max);
	viewer->SetColorLevel(max/2.0);

	viewer->SetupInteractor(iren);
	viewer->Render();
  
	iren->Initialize();
	iren->Start();


I tried a .png image file and it worked very well. I couldn't find out the reason why the parameters of VTK image data changed. How should I do?

Thank you very much!

xin