Hello all,
I am a beginner in VTK.
I have a brainDTI image in .nrrd format. I want to extract the principal eigenvalues from the that image and create a separate vector image.
First of all, I tried reading the .nrrd image using different vtk classes like vtkStructuredPointsReader , vtkXMLPolyDataReader and vtkPolyDataReader even vtkNrrdImageReader or so. But none of them works.
I tried to create the vector image using slicer3D tool’s DTIProcess extension and generated a .vtk file.
#include <vtkSmartPointer.h>
#include <vtkXMLPolyDataReader.h>
#include <vtkNrrdReader.h>
#include <vtkPolyData.h>
#include <vtkRenderer.h>
#include <vtkRenderWindow.h>
#include <vtkPolyDataMapper.h>
#include <vtkActor.h>
#include <vtkStructuredPointsReader.h>
#include <vtkArrowSource.h>
#include <vtkGlyph3D.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkPolyDataReader.h>
#include <vtkProperty.h>
#include <vtkImageDataGeometryFilter.h>
#include <vtkPolyDataNormals.h>
#include <vtkQuadricDecimation.h>
// all the includes
int main(int argc, char *argv[])
{
//read file:
//vtkSmartPointer <vtkNrrdReader>reader = vtkSmartPointer<vtkNrrdReader>::New();
// vtkSmartPointer<vtkXMLPolyDataReader>reader = vtkSmartPointer<vtkXMLPolyDataReader>::New();
//vtkSmartPointer<vtkPolyDataReader> reader = vtkSmartPointer<vtkPolyDataReader>::New();
vtkSmartPointer<vtkStructuredPointsReader> reader = vtkSmartPointer<vtkStructuredPointsReader>::New();
reader->SetFileName("../PEoutput.vtk");
reader->Update();
std::cout<<"Here@@@@@ "<<std::endl;
std::cout<<reader->GetOutput()->GetPoints()->GetNumberOfPoints()<<std::endl;
vtkSmartPointer<vtkImageDataGeometryFilter>geometryFilter = vtkSmartPointer<vtkImageDataGeometryFilter>::New();
geometryFilter->SetInputConnection(reader->GetOutputPort());
geometryFilter->Update();
vtkSmartPointer<vtkQuadricDecimation> decimationFilter = vtkSmartPointer<vtkQuadricDecimation>::New();
decimationFilter->SetInputData(geometryFilter->GetOutput());
decimationFilter->SetTargetReduction(0.1);
decimationFilter->Update();
std::cout << decimationFilter->GetOutput()->GetNumberOfPoints() << std::endl ;
// vtkMapper for object geometry mapping to rendering basics
vtkSmartPointer <vtkPolyDataMapper> mapper = vtkSmartPointer<vtkPolyDataMapper>::New();
//mapper->SetInputConnection(reader->GetOutputPort());
mapper->SetInputConnection(geometryFilter->GetOutputPort());
vtkSmartPointer<vtkActor> actor = vtkSmartPointer<vtkActor>::New();
actor->SetMapper(mapper);
actor->GetProperty()->SetColor ( 1, 0, 0 ) ;
// Compute & Visualize Normal Vectors
vtkSmartPointer < vtkPolyDataNormals > normalsFilter = vtkSmartPointer < vtkPolyDataNormals > ::New() ;
normalsFilter->SetInputData (decimationFilter->GetOutput());//decimationFilter
normalsFilter->ComputePointNormalsOn() ;
normalsFilter->Update();
vtkSmartPointer<vtkArrowSource>oneArrow = vtkSmartPointer<vtkArrowSource>::New();
oneArrow->Update();
vtkSmartPointer<vtkGlyph3D>lotsOfArrows = vtkSmartPointer<vtkGlyph3D>::New();
lotsOfArrows->SetSourceData(oneArrow->GetOutput());
lotsOfArrows->SetInputData(geometryFilter->GetOutput()); //reader
lotsOfArrows->OrientOn(); //
lotsOfArrows->SetVectorModeToUseNormal();
lotsOfArrows->SetScaleFactor(5);
lotsOfArrows->Update();
vtkSmartPointer < vtkPolyDataMapper > arrowMapper = vtkSmartPointer < vtkPolyDataMapper > ::New();
arrowMapper->SetInputData ( lotsOfArrows->GetOutput()) ;
//One actor for all of the arrows:
vtkSmartPointer < vtkActor > arrowActor = vtkSmartPointer < vtkActor >::New() ;
arrowActor->SetMapper ( arrowMapper ) ;
arrowActor->GetProperty()->SetColor ( 0, 0, 1 );
// vtkRenderer for collecting the items in the scene
vtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New() ;
vtkSmartPointer<vtkRenderWindow> renderWindow = vtkSmartPointer<vtkRenderWindow>::New() ;
renderWindow->AddRenderer(renderer);
vtkSmartPointer<vtkRenderWindowInteractor> interactor = vtkSmartPointer<vtkRenderWindowInteractor>::New();
interactor->SetRenderWindow(renderWindow);
renderer->AddActor(arrowActor);
// step 5: add the arrow actor to the scene
//renderer->AddActor ( actor ); //arrowActor
renderer->SetBackground( 1, 1, 1);
// vtkRenderWindow for the window
//renderWindow->AddRenderer ( renderer ) ;
renderWindow->Render();
//renderWindow->SetSize ( 300, 300 ) ;
// vtkRenderWindowInteractor for user interactions
//vtkSmartPointer < vtkRenderWindowInteractor > interactor = vtkSmartPointer < vtkRenderWindowInteractor >::New() ;
// interactor->SetRenderWindow ( renderWindow ) ;
interactor->Start() ;
return 0;
}
As a beginner I would appreciate any help…
Thanks in advance.