# ImageMapper

VTKExamples/Cxx/Visualization/ImageMapper

### Description

This example demonstrates how to display an image in 2D. The size and position are in screen coordinates.

### Code

ImageMapper.cxx

    #include <vtkVersion.h>
    #include <vtkImageData.h>
    #include <vtkSmartPointer.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkInteractorStyleImage.h>
    #include <vtkRenderer.h>
    #include <vtkImageMapper.h>
    #include <vtkActor2D.h>
    #include <vtkImageSlice.h>

    static void CreateColorImage(vtkImageData*);

    int main(int, char *[])
    {
      vtkSmartPointer<vtkImageData> colorImage = vtkSmartPointer<vtkImageData>::New();
      CreateColorImage(colorImage);

      vtkSmartPointer<vtkImageMapper> imageMapper = vtkSmartPointer<vtkImageMapper>::New();
    #if VTK_MAJOR_VERSION <= 5
      imageMapper->SetInputConnection(colorImage->GetProducerPort());
    #else
      imageMapper->SetInputData(colorImage);
    #endif
      imageMapper->SetColorWindow(255);
      imageMapper->SetColorLevel(127.5);

      vtkSmartPointer<vtkActor2D> imageActor = vtkSmartPointer<vtkActor2D>::New();
      imageActor->SetMapper(imageMapper);
      imageActor->SetPosition(20, 20);

      // Setup renderers
      vtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New();

      // 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);

      //renderer->AddViewProp(imageActor);
      renderer->AddActor2D(imageActor);

      renderWindow->Render();
      renderWindowInteractor->Start();

      return EXIT_SUCCESS;
    }

    void CreateColorImage(vtkImageData* image)
    {
      unsigned int dim = 20;

      image->SetDimensions(dim, dim, 1);
    #if VTK_MAJOR_VERSION <= 5
      image->SetNumberOfScalarComponents(3);
      image->SetScalarTypeToUnsignedChar();
      image->AllocateScalars();
    #else
      image->AllocateScalars(VTK_UNSIGNED_CHAR,3);
    #endif
      for(unsigned int x = 0; x < dim; x++)
      {
        for(unsigned int y = 0; y < dim; y++)
        {
          unsigned char* pixel = static_cast<unsigned char*>(image->GetScalarPointer(x,y,0));
          if(x < dim/2)
          {
        pixel[0] = 255;
        pixel[1] = 0;
          }
          else
          {
        pixel[0] = 0;
        pixel[1] = 255;
          }

          pixel[2] = 0;
        }
      }

      image->Modified();
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(ImageMapper)

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

    add_executable(ImageMapper MACOSX_BUNDLE ImageMapper.cxx)

    target_link_libraries(ImageMapper ${VTK_LIBRARIES})

### Download and Build ImageMapper

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

    cd ImageMapper/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:

    ./ImageMapper

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