InteractWithImage

Description¶

This example shows how to display an image and zoom/pan/adjust brightness interactively.

Question

If you have a question about this example, please use the VTK Discourse Forum

Code¶

InteractWithImage.cxx

#include <vtkImageActor.h> // Note: this is a 3D actor (c.f. vtkImageMapper which is 2D)
#include <vtkImageMapper3D.h>
#include <vtkImageReader2.h>
#include <vtkImageReader2Factory.h>
#include <vtkInteractorStyleImage.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSmartPointer.h>

int main(int argc, char* argv[])
{
  vtkNew<vtkNamedColors> colors;

  // Parse input arguments
  if (argc != 2)
  {
    std::cout << "Required parameters: Filename e.g. Ox.jpg" << std::endl;
    return EXIT_FAILURE;
  }

  // Read the image.
  vtkNew<vtkImageReader2Factory> readerFactory;
  vtkSmartPointer<vtkImageReader2> reader;
  reader.TakeReference(readerFactory->CreateImageReader2(argv[1]));
  reader->SetFileName(argv[1]);

  // Create an actor.
  vtkNew<vtkImageActor> actor;
  actor->GetMapper()->SetInputConnection(reader->GetOutputPort());

  // Setup renderer.
  vtkNew<vtkRenderer> renderer;
  renderer->AddActor(actor);
  renderer->ResetCamera();
  renderer->SetBackground(colors->GetColor3d("Peru").GetData());

  // Setup render window.
  vtkNew<vtkRenderWindow> window;
  window->AddRenderer(renderer);
  window->SetWindowName("InteractWithImage");

  // Setup render window interactor.
  vtkNew<vtkRenderWindowInteractor> interactor;
  interactor->SetRenderWindow(window);

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

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

  return EXIT_SUCCESS;
}

CMakeLists.txt¶

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(InteractWithImage)

find_package(VTK COMPONENTS 
  CommonColor
  CommonCore
  IOImage
  InteractionStyle
  RenderingContextOpenGL2
  RenderingCore
  RenderingFreeType
  RenderingGL2PSOpenGL2
  RenderingOpenGL2
)

if (NOT VTK_FOUND)
  message(FATAL_ERROR "InteractWithImage: Unable to find the VTK build folder.")
endif()

# Prevent a "command line is too long" failure in Windows.
set(CMAKE_NINJA_FORCE_RESPONSE_FILE "ON" CACHE BOOL "Force Ninja to use response files.")
add_executable(InteractWithImage MACOSX_BUNDLE InteractWithImage.cxx )
  target_link_libraries(InteractWithImage PRIVATE ${VTK_LIBRARIES}
)
# vtk_module_autoinit is needed
vtk_module_autoinit(
  TARGETS InteractWithImage
  MODULES ${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

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