# ImageShrink3D

VTKExamples/Cxx/Images/ImageShrink3D

### Code

ImageShrink3D.cxx

    #include <vtkSmartPointer.h>
    #include <vtkImageData.h>
    #include <vtkImageMapper3D.h>
    #include <vtkImageShrink3D.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkInteractorStyleImage.h>
    #include <vtkRenderer.h>
    #include <vtkImageActor.h>
    #include <vtkImageEllipsoidSource.h>
    #include <vtkImageCast.h>

    int main(int, char *[])
    {
      // Create an image
      vtkSmartPointer<vtkImageEllipsoidSource> source =
        vtkSmartPointer<vtkImageEllipsoidSource>::New();
      source->SetWholeExtent(0, 20, 0, 20, 0, 0);
      source->SetCenter(10,10,0);
      source->SetRadius(3,4,0);
      source->Update();

      vtkSmartPointer<vtkImageShrink3D> shrinkFilter =
        vtkSmartPointer<vtkImageShrink3D>::New();
      shrinkFilter->SetInputConnection(source->GetOutputPort());
      shrinkFilter->SetShrinkFactors(2,1,1);
      shrinkFilter->Update();

       // Create actors
      vtkSmartPointer<vtkImageActor> originalActor =
        vtkSmartPointer<vtkImageActor>::New();
      originalActor->GetMapper()->SetInputConnection(
        source->GetOutputPort());

      vtkSmartPointer<vtkImageActor> shrunkActor =
        vtkSmartPointer<vtkImageActor>::New();
      shrunkActor->GetMapper()->SetInputConnection(
        shrinkFilter->GetOutputPort());

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

      // Setup renderers
      vtkSmartPointer<vtkRenderer> originalRenderer =
        vtkSmartPointer<vtkRenderer>::New();
      originalRenderer->SetViewport(originalViewport);
      originalRenderer->AddActor(originalActor);
      originalRenderer->ResetCamera();
      originalRenderer->SetBackground(.4, .5, .6);

      vtkSmartPointer<vtkRenderer> shrunkRenderer =
        vtkSmartPointer<vtkRenderer>::New();
      shrunkRenderer->SetViewport(shrunkViewport);
      shrunkRenderer->AddActor(shrunkActor);
      shrunkRenderer->ResetCamera();
      shrunkRenderer->SetBackground(.4, .5, .7);

      vtkSmartPointer<vtkRenderWindow> renderWindow =
        vtkSmartPointer<vtkRenderWindow>::New();
      renderWindow->SetSize(600, 300);
      renderWindow->AddRenderer(originalRenderer);
      renderWindow->AddRenderer(shrunkRenderer);

      vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
      vtkSmartPointer<vtkInteractorStyleImage> style =
        vtkSmartPointer<vtkInteractorStyleImage>::New();

      renderWindowInteractor->SetInteractorStyle(style);

      renderWindowInteractor->SetRenderWindow(renderWindow);
      renderWindowInteractor->Initialize();

      renderWindowInteractor->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(ImageShrink3D)

    find_package(VTK REQUIRED)
    include(${VTK_USE_FILE})

    add_executable(ImageShrink3D MACOSX_BUNDLE ImageShrink3D.cxx )

    target_link_libraries(ImageShrink3D ${VTK_LIBRARIES})

### Download and Build ImageShrink3D

Click here to download ImageShrink3D and its CMakeLists.txt file. Once the tarball ImageShrink3D.tar has been downloaded and extracted,

    cd ImageShrink3D/build

If VTK is installed:

    cmake ..

If VTK is not installed but compiled on your system, you will need to specify the path to your VTK build:

    cmake -DVTK_DIR:PATH=/home/me/vtk_build ..

Build the project:

    make

and run it:

    ./ImageShrink3D

WINDOWS USERS

Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.