# BorderPixelSize

VTKExamples/Cxx/Images/BorderPixelSize

### Code

BorderPixelSize.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 <vtkImageSliceMapper.h>
    #include <vtkImageSlice.h>
    #include <vtkImageProperty.h>

    static void CreateRandomImage(vtkImageData* image, const unsigned int dimension);

    int main(int, char *[])
    {
      // Big image
      vtkSmartPointer<vtkImageData> image = vtkSmartPointer<vtkImageData>::New();
      CreateRandomImage(image, 50);

      vtkSmartPointer<vtkImageSliceMapper> imageSliceMapper = vtkSmartPointer<vtkImageSliceMapper>::New();
    #if VTK_MAJOR_VERSION <= 5
      imageSliceMapper->SetInputConnection(image->GetProducerPort());
    #else
      imageSliceMapper->SetInputData(image);
    #endif
      imageSliceMapper->BorderOn(); // This line tells the mapper to draw the full border pixels.
      vtkSmartPointer<vtkImageSlice> imageSlice = vtkSmartPointer<vtkImageSlice>::New();
      imageSlice->SetMapper(imageSliceMapper);
      imageSlice->GetProperty()->SetInterpolationTypeToNearest();

      vtkSmartPointer<vtkRenderer> renderer = vtkSmartPointer<vtkRenderer>::New();
      renderer->AddViewProp(imageSlice);
      renderer->ResetCamera();

      vtkSmartPointer<vtkRenderWindow> renderWindow = vtkSmartPointer<vtkRenderWindow>::New();
      renderWindow->AddRenderer(renderer);

      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;
    }

    void CreateRandomImage(vtkImageData* image, const unsigned int dimension)
    {
      image->SetDimensions(dimension, dimension, 1);
      image->SetOrigin(.5,.5,0);
    #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 < dimension; x++)
      {
        for(unsigned int y = 0; y < dimension; y++)
        {
          unsigned char* pixel = static_cast<unsigned char*>(image->GetScalarPointer(x,y,0));
          pixel[0] = rand() % 255;
          pixel[1] = rand() % 255;
          pixel[2] = rand() % 255;
        }
      }

      image->Modified();
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(BorderPixelSize)

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

    add_executable(BorderPixelSize MACOSX_BUNDLE BorderPixelSize.cxx)

    target_link_libraries(BorderPixelSize ${VTK_LIBRARIES})

### Download and Build BorderPixelSize

Danger

The generation of tar files has not been ported to the new VTKExamples. Some tarballs may be missing or out-of-date.

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

    cd BorderPixelSize/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:

    ./BorderPixelSize

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.