ITK/Examples/ImageProcessing/AbsImageFilter

AbsImageFilter.cxx

<source lang="cpp">

1. include "itkImage.h"
2. include "itkImageFileWriter.h"
3. include "itkRescaleIntensityImageFilter.h"
4. include "itkAbsImageFilter.h"

1. include <itkImageToVTKImageFilter.h>

1. include "vtkImageViewer.h"
2. include "vtkRenderWindowInteractor.h"
3. include "vtkSmartPointer.h"
4. include "vtkImageActor.h"
5. include "vtkInteractorStyleImage.h"
6. include "vtkRenderer.h"
7. include "vtkCamera.h"

typedef itk::Image<unsigned char, 2> UnsignedCharImageType; typedef itk::Image<float, 2> FloatImageType;

static void CreateImage(FloatImageType::Pointer image);

int main(int, char *[]) {

 FloatImageType::Pointer image = FloatImageType::New();
 CreateImage(image);

 // Rescale the image so that it can be displayed
 typedef itk::RescaleIntensityImageFilter< FloatImageType, UnsignedCharImageType > FloatRescaleCastFilterType;
 FloatRescaleCastFilterType::Pointer rescaleFilter = FloatRescaleCastFilterType::New();
 rescaleFilter->SetInput(image);
 rescaleFilter->SetOutputMinimum(0);
 rescaleFilter->SetOutputMaximum(255);
 rescaleFilter->Update();

 // Take the absolute value of the image
 typedef itk::AbsImageFilter <FloatImageType, UnsignedCharImageType>
         AbsImageFilterType;

 AbsImageFilterType::Pointer absFilter
         = AbsImageFilterType::New ();
 absFilter->SetInput(image);
 absFilter->Update();

 typedef itk::RescaleIntensityImageFilter< UnsignedCharImageType, UnsignedCharImageType > RescaleFilterType;
 RescaleFilterType::Pointer absRescaleFilter = RescaleFilterType::New();
 absRescaleFilter->SetInput(absFilter->GetOutput());
 absRescaleFilter->SetOutputMinimum(0);
 absRescaleFilter->SetOutputMaximum(255);
 absRescaleFilter->Update();

 // Visualize input image
 typedef itk::ImageToVTKImageFilter<UnsignedCharImageType> ConnectorType;
 ConnectorType::Pointer originalConnector = ConnectorType::New();
 originalConnector->SetInput(rescaleFilter->GetOutput());

 vtkSmartPointer<vtkImageActor> actor =
   vtkSmartPointer<vtkImageActor>::New();
 actor->SetInput(originalConnector->GetOutput());

 // Visualize abs image
 ConnectorType::Pointer absConnector = ConnectorType::New();
 absConnector->SetInput(absRescaleFilter->GetOutput());

 vtkSmartPointer<vtkImageActor> absActor =
   vtkSmartPointer<vtkImageActor>::New();
 absActor->SetInput(absConnector->GetOutput());

 // There will be one render window
 vtkSmartPointer<vtkRenderWindow> renderWindow =
   vtkSmartPointer<vtkRenderWindow>::New();
 renderWindow->SetSize(600, 300);

 vtkSmartPointer<vtkRenderWindowInteractor> interactor =
   vtkSmartPointer<vtkRenderWindowInteractor>::New();
 interactor->SetRenderWindow(renderWindow);

 // Define viewport ranges
 // (xmin, ymin, xmax, ymax)
 double leftViewport[4] = {0.0, 0.0, 0.5, 1.0};
 double rightViewport[4] = {0.5, 0.0, 1.0, 1.0};

 // Setup both renderers
 vtkSmartPointer<vtkRenderer> leftRenderer =
   vtkSmartPointer<vtkRenderer>::New();
 renderWindow->AddRenderer(leftRenderer);
 leftRenderer->SetViewport(leftViewport);
 leftRenderer->SetBackground(.6, .5, .4);

 vtkSmartPointer<vtkRenderer> rightRenderer =
   vtkSmartPointer<vtkRenderer>::New();
 renderWindow->AddRenderer(rightRenderer);
 rightRenderer->SetViewport(rightViewport);
 rightRenderer->SetBackground(.4, .5, .6);

 // Add the sphere to the left and the cube to the right
 leftRenderer->AddActor(actor);
 rightRenderer->AddActor(absActor);
 leftRenderer->GetActiveCamera()->SetViewUp(0,-1,0);
 leftRenderer->ResetCamera();

 rightRenderer->GetActiveCamera()->SetViewUp(0,-1,0);
 rightRenderer->ResetCamera();

 renderWindow->Render();

 vtkSmartPointer<vtkInteractorStyleImage> style =
   vtkSmartPointer<vtkInteractorStyleImage>::New();
 interactor->SetInteractorStyle(style);

 interactor->Start();

 return EXIT_SUCCESS;

}

void CreateImage(FloatImageType::Pointer image) {

 // Create an image with negative values
 FloatImageType::RegionType region;
 FloatImageType::IndexType start;
 start[0] = 0;
 start[1] = 0;

 FloatImageType::SizeType size;
 size[0] = 200;
 size[1] = 300;

 region.SetSize(size);
 region.SetIndex(start);

 image->SetRegions(region);
 image->Allocate();

 itk::ImageRegionIterator<FloatImageType> imageIterator(image,region);

 while(!imageIterator.IsAtEnd())
   {
   imageIterator.Set(imageIterator.GetIndex()[0] - imageIterator.GetIndex()[1]);
   ++imageIterator;
   }

} </source>

CMakeLists.txt

<source lang="cmake"> cmake_minimum_required(VERSION 2.6)

PROJECT(AbsImageFilter)

include_directories(/home/doriad/src/ITK/Wrapping/WrapITK/ExternalProjects/ItkVtkGlue/src/)

FIND_PACKAGE(VTK REQUIRED) INCLUDE(${VTK_USE_FILE})

FIND_PACKAGE(ITK REQUIRED) INCLUDE(${ITK_USE_FILE})

ADD_EXECUTABLE(AbsImageFilter AbsImageFilter.cxx) TARGET_LINK_LIBRARIES(AbsImageFilter vtkHybrid ITKBasicFilters ITKCommon ITKIO)

</source>