PNGReader

vtk-examples/Cxx/IO/PNGReader

Description¶

This example demonstrates how to read a PNG image file.

Other languages

See (Java), (CSharp)

Question

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

Code¶

PNGReader.cxx

#include <vtkImageViewer2.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkPNGReader.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>

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

  // Verify input arguments
  if (argc < 2)
  {
    std::cout << "Usage: " << argv[0] << " Filename(.png) e.g. Gourds.png"
              << std::endl;
    return EXIT_FAILURE;
  }

  // Read the image
  vtkNew<vtkPNGReader> reader;
  reader->SetFileName(argv[1]);

  // Visualize
  vtkNew<vtkImageViewer2> imageViewer;
  imageViewer->SetInputConnection(reader->GetOutputPort());
  vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;
  imageViewer->SetupInteractor(renderWindowInteractor);
  imageViewer->Render();
  imageViewer->GetRenderer()->ResetCamera();
  imageViewer->GetRenderer()->SetBackground(
      colors->GetColor3d("DarkSlateGray").GetData());
  imageViewer->GetRenderWindow()->SetWindowName("PNGReader");
  imageViewer->Render();

  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt¶

cmake_minimum_required(VERSION 3.12 FATAL_ERROR)

project(PNGReader)

find_package(VTK COMPONENTS 
)

if (NOT VTK_FOUND)
  message(FATAL_ERROR "PNGReader: 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(PNGReader MACOSX_BUNDLE PNGReader.cxx )
  target_link_libraries(PNGReader PRIVATE ${VTK_LIBRARIES}
)
# vtk_module_autoinit is needed
vtk_module_autoinit(
  TARGETS PNGReader
  MODULES ${VTK_LIBRARIES}
)

Download and Build PNGReader¶

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

cd PNGReader/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:

./PNGReader

WINDOWS USERS

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