text: /*=========================================================================
   *
   *  Copyright NumFOCUS
   *
   *  Licensed under the Apache License, Version 2.0 (the "License");
   *  you may not use this file except in compliance with the License.
   *  You may obtain a copy of the License at
   *
   *         http://www.apache.org/licenses/LICENSE-2.0.txt
   *
   *  Unless required by applicable law or agreed to in writing, software
   *  distributed under the License is distributed on an "AS IS" BASIS,
   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   *  See the License for the specific language governing permissions and
   *  limitations under the License.
   *
   *=========================================================================*/
  
  #include "itkBinaryImageToLevelSetImageAdaptor.h"
  #include "itkImageFileReader.h"
  #include "itkLevelSetIterationUpdateCommand.h"
  #include "itkLevelSetContainer.h"
  #include "itkLevelSetEquationChanAndVeseInternalTerm.h"
  #include "itkLevelSetEquationChanAndVeseExternalTerm.h"
  #include "itkLevelSetEquationContainer.h"
  #include "itkLevelSetEquationTermContainer.h"
  #include "itkLevelSetEvolution.h"
  #include "itkLevelSetEvolutionNumberOfIterationsStoppingCriterion.h"
  #include "itkLevelSetDenseImage.h"
  #include "itkVTKVisualize2DLevelSetAsElevationMap.h"
  #include "itkSinRegularizedHeavisideStepFunction.h"
  
  #include "itkOtsuMultipleThresholdsImageFilter.h"
  #include "itkRescaleIntensityImageFilter.h"
  #include "vtkRenderWindowInteractor.h"
  
  int
  main(int argc, char * argv[])
  {
    if (argc != 3)
    {
      std::cerr << "Missing Arguments" << std::endl;
      std::cerr << argv[0] << std::endl;
      std::cerr << "<Input Image> <Interactive (0 or 1)>" << std::endl;
      return EXIT_FAILURE;
    }
  
    // Image Dimension
    constexpr unsigned int Dimension = 2;
  
    using InputPixelType = unsigned char;
    using InputImageType = itk::Image<InputPixelType, Dimension>;
  
    InputImageType::Pointer input = itk::ReadImage<InputImageType>(argv[1]);
  
    using LevelSetPixelType = float;
    using LevelSetImageType = itk::Image<LevelSetPixelType, Dimension>;
    using LevelSetType = itk::LevelSetDenseImage<LevelSetImageType>;
  
    // Generate a binary mask that will be used as initialization for the level
    // set evolution.
    using OtsuFilterType = itk::OtsuMultipleThresholdsImageFilter<InputImageType, LevelSetImageType>;
    OtsuFilterType::Pointer otsu = OtsuFilterType::New();
    otsu->SetInput(input);
    otsu->SetNumberOfHistogramBins(256);
    otsu->SetNumberOfThresholds(1);
  
    using RescaleType = itk::RescaleIntensityImageFilter<LevelSetImageType, LevelSetImageType>;
    RescaleType::Pointer rescaler = RescaleType::New();
    rescaler->SetInput(otsu->GetOutput());
    rescaler->SetOutputMinimum(0);
    rescaler->SetOutputMaximum(1);
  
    // convert a binary mask to a level-set function
    using BinaryImageToLevelSetType = itk::BinaryImageToLevelSetImageAdaptor<LevelSetImageType, LevelSetType>;
  
    BinaryImageToLevelSetType::Pointer adaptor = BinaryImageToLevelSetType::New();
    adaptor->SetInputImage(rescaler->GetOutput());
    adaptor->Initialize();
  
    LevelSetType::Pointer levelSet = adaptor->GetModifiableLevelSet();
  
    // Create the visualizer
    using VisualizationType = itk::VTKVisualize2DLevelSetAsElevationMap<InputImageType, LevelSetType>;
    VisualizationType::Pointer visualizer = VisualizationType::New();
    visualizer->SetInputImage(input);
    visualizer->SetLevelSet(levelSet);
  
    vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor = vtkSmartPointer<vtkRenderWindowInteractor>::New();
    renderWindowInteractor->SetRenderWindow(visualizer->GetRenderWindow());
  
    try
    {
      visualizer->Update();
    }
    catch (itk::ExceptionObject & error)
    {
      std::cerr << "Error: " << error << std::endl;
      return EXIT_FAILURE;
    }
  
    bool interactive = (std::stoi(argv[2]) != 0);
    if (interactive)
    {
      renderWindowInteractor->Start();
    }
  
    return EXIT_SUCCESS;
  }
  