# Cast

VTKExamples/Cxx/Images/Cast

### Description

Cast an image to a different type.

### Code

Cast.cxx

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

    int main(int, char *[])
    {
      // Create a float image
      vtkSmartPointer<vtkImageMandelbrotSource> source =
        vtkSmartPointer<vtkImageMandelbrotSource>::New();
      source->Update();

      std::cout << source->GetOutput()->GetScalarTypeAsString() << std::endl;

      vtkSmartPointer<vtkImageCast> castFilter =
        vtkSmartPointer<vtkImageCast>::New();
      castFilter->SetInputConnection(source->GetOutputPort());
      castFilter->SetOutputScalarTypeToUnsignedChar();
      castFilter->Update();

      // Create an actor
      vtkSmartPointer<vtkImageActor> actor =
        vtkSmartPointer<vtkImageActor>::New();
      actor->GetMapper()->SetInputConnection(castFilter->GetOutputPort());

      // Setup renderer
      vtkSmartPointer<vtkRenderer> renderer =
        vtkSmartPointer<vtkRenderer>::New();
      renderer->AddActor(actor);
      renderer->ResetCamera();

      // Setup render window
      vtkSmartPointer<vtkRenderWindow> renderWindow =
        vtkSmartPointer<vtkRenderWindow>::New();
      renderWindow->AddRenderer(renderer);

      // Setup render window interactor
      vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
      vtkSmartPointer<vtkInteractorStyleImage> style =
        vtkSmartPointer<vtkInteractorStyleImage>::New();

      renderWindowInteractor->SetInteractorStyle(style);

      // Render and start interaction
      renderWindowInteractor->SetRenderWindow(renderWindow);
      renderWindowInteractor->Initialize();

      renderWindowInteractor->Start();
      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(Cast)

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

    add_executable(Cast MACOSX_BUNDLE Cast.cxx )

    target_link_libraries(Cast ${VTK_LIBRARIES})

### Download and Build Cast

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

    cd Cast/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:

    ./Cast

WINDOWS USERS

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