SphinxExamples/src/Filtering/BinaryMathematicalMorphology/OpeningBinaryImage/Code.cxx

/*=========================================================================
 *
 *  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
 *
 *         https://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 "itkBinaryMorphologicalOpeningImageFilter.h"
#include "itkImageFileReader.h"
#include "itkImageFileWriter.h"
#include "itkBinaryBallStructuringElement.h"
#include "itkSubtractImageFilter.h"
 
#ifdef ENABLE_QUICKVIEW
#  include "QuickView.h"
#endif
 
namespace
{
using ImageType = itk::Image<unsigned char, 2>;
}
 
static void
CreateImage(ImageType * const image);
 
int
main(int argc, char * argv[])
{
  ImageType::Pointer image;
  unsigned int       radius = 5;
  std::string        outputFilename = "Output.png";
 
  if (argc >= 4)
  {
    image = itk::ReadImage<ImageType>(argv[1]);
 
    std::stringstream ss(argv[2]);
    ss >> radius;
 
    outputFilename = argv[3];
  }
  else
  {
    image = ImageType::New();
    CreateImage(image);
  }
 
  std::cout << "Radius: " << radius << std::endl;
  using StructuringElementType = itk::BinaryBallStructuringElement<ImageType::PixelType, ImageType::ImageDimension>;
  StructuringElementType structuringElement;
  structuringElement.SetRadius(radius);
  structuringElement.CreateStructuringElement();
 
  using BinaryMorphologicalOpeningImageFilterType =
    itk::BinaryMorphologicalOpeningImageFilter<ImageType, ImageType, StructuringElementType>;
  auto openingFilter = BinaryMorphologicalOpeningImageFilterType::New();
  openingFilter->SetInput(image);
  openingFilter->SetKernel(structuringElement);
  openingFilter->Update();
 
  using SubtractType = itk::SubtractImageFilter<ImageType>;
  auto diff = SubtractType::New();
  diff->SetInput1(image);
  diff->SetInput2(openingFilter->GetOutput());
 
#ifdef ENABLE_QUICKVIEW
  QuickView         viewer;
  std::stringstream desc;
  desc << "Original ";
  viewer.AddImage(image.GetPointer(), true, desc.str());
 
  std::stringstream desc2;
  desc2 << "BinaryOpening, radius = " << radius;
  viewer.AddImage(openingFilter->GetOutput(), true, desc2.str());
 
  std::stringstream desc3;
  desc3 << "Original - BinaryOpening";
  viewer.AddImage(diff->GetOutput(), true, desc3.str());
  viewer.Visualize();
#endif
 
  itk::WriteImage(openingFilter->GetOutput(), outputFilename);
 
  return EXIT_SUCCESS;
}
 
 
void
CreateImage(ImageType * const image)
{
  // Create an image with 2 connected components
  itk::Index<2> corner = { { 0, 0 } };
 
  itk::Size<2> size;
  unsigned int NumRows = 200;
  unsigned int NumCols = 300;
  size[0] = NumRows;
  size[1] = NumCols;
 
  itk::ImageRegion<2> region(corner, size);
 
  image->SetRegions(region);
  image->Allocate(true);
 
  // Make a square
  for (unsigned int r = 40; r < 100; ++r)
  {
    for (unsigned int c = 40; c < 100; ++c)
    {
      itk::Index<2> pixelIndex;
      pixelIndex[0] = r;
      pixelIndex[1] = c;
 
      image->SetPixel(pixelIndex, 50);
    }
  }
}