# InteractWithImage

VTKExamples/Cxx/Images/InteractWithImage

### Description

This example shows how to display an image and zoom/pan/adjust brightness interactively. A picture of the bunny is provided for the demo.

### Code

InteractWithImage.cxx

    #include <vtkJPEGReader.h>
    #include <vtkImageMapper3D.h>
    #include <vtkImageActor.h> // Note: this is a 3D actor (c.f. vtkImageMapper which is 2D)
    #include <vtkRenderer.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkInteractorStyleImage.h>
    #include <vtkSmartPointer.h>

    int main(int argc, char* argv[])
    {
      // Parse input arguments
      if ( argc != 2 )
      {
        std::cout << "Required parameters: Filename" << std::endl;
        return EXIT_FAILURE;
      }
      std::string inputFilename = argv[1];

      // Read the image
      vtkSmartPointer<vtkJPEGReader> reader =
          vtkSmartPointer<vtkJPEGReader>::New();
      reader->SetFileName(inputFilename.c_str());
      reader->Update();

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

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

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

      // Setup render window interactor
      vtkSmartPointer<vtkRenderWindowInteractor> interactor =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
      interactor->SetRenderWindow(window);

      // Setup interactor style (this is what implements the zooming, panning and brightness adjustment functionality)
      vtkSmartPointer<vtkInteractorStyleImage> style =
        vtkSmartPointer<vtkInteractorStyleImage>::New();
      interactor->SetInteractorStyle(style);

      // Render and start interaction
      interactor->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(InteractWithImage)

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

    add_executable(InteractWithImage MACOSX_BUNDLE InteractWithImage.cxx)

    target_link_libraries(InteractWithImage ${VTK_LIBRARIES})

### Download and Build InteractWithImage

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

    cd InteractWithImage/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:

    ./InteractWithImage

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.