WritePNM

VTKEx/Cxx/IO/WritePNM

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Question

If you have a simple question about this example contact us at VTKExProject If your question is more complex and may require extended discussion, please use the VTK Discourse Forum

Code¶

WritePNM.cxx

#include <vtkImageData.h>
#include <vtkPNMWriter.h>
#include <vtkSmartPointer.h>
#include <vtkImageCanvasSource2D.h>
#include <vtkSmartPointer.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkImageActor.h>
#include <vtkImageMapper3D.h>
#include <vtkPNMReader.h>
#include <vtkInteractorStyleImage.h>

int main(int argc, char *argv[])
{
  if(argc != 2)
  {
    std::cout << "Required parameters: OutputFilename.pnm" << std::endl;
    return EXIT_FAILURE;
  }

  std::string filename = argv[1];

  vtkSmartPointer<vtkImageCanvasSource2D> imageSource =
    vtkSmartPointer<vtkImageCanvasSource2D>::New();
  imageSource->SetScalarTypeToUnsignedChar();
  imageSource->SetExtent(0,9,0,9,0,0);
  imageSource->SetNumberOfScalarComponents(3);
  imageSource->SetDrawColor(0, 0, 0, 0);
  imageSource->FillBox(0,9,0,9);
  imageSource->SetDrawColor(255, 0, 0, 0);
  imageSource->FillBox(5,7,5,7);
  imageSource->Update();

  vtkSmartPointer<vtkPNMWriter> pnmWriter =
    vtkSmartPointer<vtkPNMWriter>::New();
  pnmWriter->SetFileName(filename.c_str());
  pnmWriter->SetInputConnection(imageSource->GetOutputPort());
  pnmWriter->Write();

  // Read and display for verification
  vtkSmartPointer<vtkPNMReader> reader =
    vtkSmartPointer<vtkPNMReader>::New();
  reader->SetFileName(filename.c_str());
  reader->Update();

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

  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt¶

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(WritePNM)

find_package(VTK COMPONENTS 
  vtkvtkCommonCore
  vtkvtkCommonDataModel
  vtkvtkIOImage
  vtkvtkImagingSources
  vtkvtkInteractionStyle
  vtkvtkRenderingContextOpenGL2
  vtkvtkRenderingCore
  vtkvtkRenderingFreeType
  vtkvtkRenderingGL2PSOpenGL2
  vtkvtkRenderingOpenGL2 QUIET)
if (NOT VTK_FOUND)
  message("Skipping WritePNM: ${VTK_NOT_FOUND_MESSAGE}")
  return ()
endif()
message (STATUS "VTK_VERSION: ${VTK_VERSION}")
if (VTK_VERSION VERSION_LESS "8.90.0")
  # old system
  include(${VTK_USE_FILE})
  add_executable(WritePNM MACOSX_BUNDLE WritePNM.cxx )
  target_link_libraries(WritePNM PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(WritePNM MACOSX_BUNDLE WritePNM.cxx )
  target_link_libraries(WritePNM PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS WritePNM
    MODULES ${VTK_LIBRARIES}
    )
endif ()

Download and Build WritePNM¶

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

cd WritePNM/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:

./WritePNM

WINDOWS USERS

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