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ImageHybridMedian2D

vtk-examples/Cxx/Images/ImageHybridMedian2D


Description

This example reads in an image and performs median filtering on it. The input and output are displayed.

Question

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

Code

ImageHybridMedian2D.cxx

#include <vtkImageAccumulate.h>
#include <vtkImageActor.h>
#include <vtkImageCast.h>
#include <vtkImageData.h>
#include <vtkImageHybridMedian2D.h>
#include <vtkImageMapper3D.h>
#include <vtkImageThreshold.h>
#include <vtkInteractorStyleImage.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;

  // Handle the arguments
  if (argc < 2)
  {
    std::cout << "Required arguments: filename.png e.g Gourds.png" << std::endl;
    return EXIT_FAILURE;
  }

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

  vtkNew<vtkImageHybridMedian2D> hybridMedian;
  hybridMedian->SetInputConnection(reader->GetOutputPort());

  vtkNew<vtkImageActor> originalActor;
  originalActor->GetMapper()->SetInputConnection(reader->GetOutputPort());

  vtkNew<vtkImageActor> hybridMedianActor;
  hybridMedianActor->GetMapper()->SetInputConnection(
      hybridMedian->GetOutputPort());

  // Define viewport ranges
  // (xmin, ymin, xmax, ymax)
  double originalViewport[4] = {0.0, 0.0, 0.5, 1.0};
  double hybridMedianViewport[4] = {0.5, 0.0, 1.0, 1.0};

  // Setup renderers
  vtkNew<vtkRenderer> originalRenderer;
  originalRenderer->SetViewport(originalViewport);
  originalRenderer->AddActor(originalActor);
  originalRenderer->ResetCamera();
  originalRenderer->SetBackground(
      colors->GetColor3d("CornflowerBlue").GetData());

  vtkNew<vtkRenderer> hybridMedianRenderer;
  hybridMedianRenderer->SetViewport(hybridMedianViewport);
  hybridMedianRenderer->AddActor(hybridMedianActor);
  hybridMedianRenderer->ResetCamera();
  hybridMedianRenderer->SetBackground(
      colors->GetColor3d("SteelBlue").GetData());

  vtkNew<vtkRenderWindow> renderWindow;
  renderWindow->SetSize(600, 300);
  renderWindow->AddRenderer(originalRenderer);
  renderWindow->AddRenderer(hybridMedianRenderer);
  renderWindow->SetWindowName("ImageHybridMedian2D");

  vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;
  vtkNew<vtkInteractorStyleImage> style;

  renderWindowInteractor->SetInteractorStyle(style);

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

  renderWindowInteractor->Start();

  return EXIT_SUCCESS;
}

CMakeLists.txt

cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

project(ImageHybridMedian2D)

find_package(VTK COMPONENTS 
  vtkCommonColor
  vtkCommonCore
  vtkCommonDataModel
  vtkIOImage
  vtkImagingCore
  vtkImagingGeneral
  vtkImagingStatistics
  vtkInteractionStyle
  vtkRenderingContextOpenGL2
  vtkRenderingCore
  vtkRenderingFreeType
  vtkRenderingGL2PSOpenGL2
  vtkRenderingOpenGL2
  QUIET
)

if (NOT VTK_FOUND)
  message("Skipping ImageHybridMedian2D: ${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(ImageHybridMedian2D MACOSX_BUNDLE ImageHybridMedian2D.cxx )
  target_link_libraries(ImageHybridMedian2D PRIVATE ${VTK_LIBRARIES})
else ()
  # include all components
  add_executable(ImageHybridMedian2D MACOSX_BUNDLE ImageHybridMedian2D.cxx )
  target_link_libraries(ImageHybridMedian2D PRIVATE ${VTK_LIBRARIES})
  # vtk_module_autoinit is needed
  vtk_module_autoinit(
    TARGETS ImageHybridMedian2D
    MODULES ${VTK_LIBRARIES}
    )
endif ()

Download and Build ImageHybridMedian2D

Click here to download ImageHybridMedian2D and its CMakeLists.txt file. Once the tarball ImageHybridMedian2D.tar has been downloaded and extracted,

cd ImageHybridMedian2D/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:

./ImageHybridMedian2D

WINDOWS USERS

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