[vtkusers] problem in estimating the curvature

[Arnaud Gelas]

Hi Martine,

vtkCurvatures processes vtkPolyData. Thus, if you want to compute 
Gaussian curvature, you have to extract one surface from your image 
(e.g. by using a Marching Cubes).

Note that you can now directly compute the Gaussian curvature of a given 
surface in itk by using 
itk::QuadEdgeMeshDiscreteGaussianCurvatureEstimator. The way to estimate 
the Gaussian curvature is less sensitive to the connectivity than the 
vtk version.

http://www.itk.org/Doxygen/html/classitk_1_1QuadEdgeMeshDiscreteGaussianCurvatureEstimator.html

Arnaud

Martine Lefevre wrote:
> Hi
> I try to estimate the curvature information of an object but I failed. 
> In run time I get vtkOutpouWindow saying there is an error in the file 
> vtkDemandDrivenPipeline.cxx.
> My input volume is an itk image that I convert to vtk image in order 
> to estimate the curvature.
> I paste my code here. Any help is appreciated.
> Thank you.
>  
> Regards
> Martine
>
>  
>
>  
>
> #include "itkImage.h"
> #include "itkImageFileReader.h"
> #include "itkImageFileWriter.h"
> #include "itkVTKImageExport.h"
> #include "itkVTKImageImport.h"
> #include "vtkImageData.h"
> #include "vtkImageImport.h"
> #include "vtkImageExport.h"
> #include "vtkCurvatures.h"
>  
> // This function will connect the given itk::VTKImageExport filter to 
> the given vtkImageImport filter.
> template <typename ITK_Exporter, typename VTK_Importer>
> void ConnectPipelines(ITK_Exporter exporter, VTK_Importer* importer)
> {
> importer->SetUpdateInformationCallback(exporter->GetUpdateInformationCallback());
> importer->SetPipelineModifiedCallback(exporter->GetPipelineModifiedCallback());
> importer->SetWholeExtentCallback(exporter->GetWholeExtentCallback());
> importer->SetSpacingCallback(exporter->GetSpacingCallback());
> importer->SetOriginCallback(exporter->GetOriginCallback());
> importer->SetScalarTypeCallback(exporter->GetScalarTypeCallback());
> importer->SetNumberOfComponentsCallback(exporter->GetNumberOfComponentsCallback());
> importer->SetPropagateUpdateExtentCallback(exporter->GetPropagateUpdateExtentCallback());
> importer->SetUpdateDataCallback(exporter->GetUpdateDataCallback());
> importer->SetDataExtentCallback(exporter->GetDataExtentCallback());
> importer->SetBufferPointerCallback(exporter->GetBufferPointerCallback());
> importer->SetCallbackUserData(exporter->GetCallbackUserData());
> }
> int main()
> {
> typedef float PixelType;
> const unsigned int Dimension = 3;
> typedef itk::Image< PixelType, Dimension > ImageType;
> typedef itk::ImageFileReader< ImageType > ReaderType;
> typedef itk::ImageFileWriter <ImageType> WriterType;
> ReaderType::Pointer reader = ReaderType::New();
> WriterType::Pointer writer = WriterType::New();
> reader->SetFileName("C:/work/MyImages/MyObject.hdr");
> // convert itk to vtk image type
> typedef itk::VTKImageExport< ImageType > ExportFilterType;
> ExportFilterType::Pointer itkExporter = ExportFilterType::New();
> itkExporter->SetInput( reader->GetOutput() );
> // Create the vtkImageImport and connect it to the itk::VTKImageExport 
> instance.
> vtkImageImport* vtkImporter = vtkImageImport::New();
> ConnectPipelines(itkExporter, vtkImporter);
> // estimate the curvature mean
> vtkCurvatures* myCurvatures= vtkCurvatures::New();
> myCurvatures->SetCurvatureTypeToGaussian();
> myCurvatures->SetInput(vtkImporter->GetOutput());
> myCurvatures->Update();
> std::cout << "end of the code !" << std::endl;
> std::cin.get();
> return 0;
> }
>
>