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 "itkImage.h"
  #include "itkImageFileReader.h"
  #include "itkSignedMaurerDistanceMapImageFilter.h"
  
  #include "itksys/SystemTools.hxx"
  #include <sstream>
  
  #ifdef ENABLE_QUICKVIEW
  #  include "QuickView.h"
  #endif
  
  using UnsignedCharImageType = itk::Image<unsigned char, 2>;
  using FloatImageType = itk::Image<float, 2>;
  
  static void
  CreateImage(UnsignedCharImageType::Pointer image);
  
  int
  main(int argc, char * argv[])
  {
    UnsignedCharImageType::Pointer image = UnsignedCharImageType::New();
    if (argc < 2)
    {
      CreateImage(image);
    }
    else
    {
      image = itk::ReadImage<UnsignedCharImageType>(argv[1]);
    }
  
    using SignedMaurerDistanceMapImageFilterType =
      itk::SignedMaurerDistanceMapImageFilter<UnsignedCharImageType, FloatImageType>;
    SignedMaurerDistanceMapImageFilterType::Pointer distanceMapImageFilter =
      SignedMaurerDistanceMapImageFilterType::New();
    distanceMapImageFilter->SetInput(image);
  
  #ifdef ENABLE_QUICKVIEW
    QuickView viewer;
    viewer.AddImage(
      image.GetPointer(), true, argc > 1 ? itksys::SystemTools::GetFilenameName(argv[1]) : "Generated image");
  
    std::stringstream desc;
    desc << "Signed Maurer Distance";
    viewer.AddImage(distanceMapImageFilter->GetOutput(), true, desc.str());
  
    viewer.Visualize();
  #endif
  
    return EXIT_SUCCESS;
  }
  
  
  void
  CreateImage(UnsignedCharImageType::Pointer image)
  {
    // Create an image
    itk::Index<2> start;
    start.Fill(0);
  
    itk::Size<2> size;
    size.Fill(100);
  
    itk::ImageRegion<2> region(start, size);
    image->SetRegions(region);
    image->Allocate();
    image->FillBuffer(0);
  
    // Create a line of white pixels
    for (unsigned int i = 40; i < 60; ++i)
    {
      itk::Index<2> pixel;
      pixel.Fill(i);
      image->SetPixel(pixel, 255);
    }
  }
  