SphinxExamples/src/Segmentation/Watersheds/SegmentWithWatershedImageFilter/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
 *
 *         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 "itkImageFileReader.h"
#include "itkImageFileWriter.h"
#include "itkScalarToRGBPixelFunctor.h"
#include "itkUnaryFunctorImageFilter.h"
#include "itkVectorGradientAnisotropicDiffusionImageFilter.h"
#include "itkWatershedImageFilter.h"
#include "itkRescaleIntensityImageFilter.h"
#include "itkScalarToRGBColormapImageFilter.h"
#include "itkGradientMagnitudeImageFilter.h"
 
// Run with:
// ./SegmentWithWatershedImageFilter inputImageFile outputImageFile threshold level
// e.g.
// ./SegmentWithWatershedImageFilter BrainProtonDensitySlice.png OutBrainWatershed.png 0.005 .5
// (A rule of thumb is to set the Threshold to be about 1 / 100 of the Level.)
 
int
main(int argc, char * argv[])
{
  if (argc < 5)
  {
    std::cerr << "Missing parameters." << std::endl;
    std::cerr << "Usage: " << argv[0] << " inputImageFile outputImageFile threshold level" << std::endl;
    return EXIT_FAILURE;
  }
 
  constexpr unsigned int Dimension = 2;
 
  using InputImageType = itk::Image<unsigned char, Dimension>;
  using FloatImageType = itk::Image<float, Dimension>;
  using RGBPixelType = itk::RGBPixel<unsigned char>;
  using RGBImageType = itk::Image<RGBPixelType, Dimension>;
  using LabeledImageType = itk::Image<itk::IdentifierType, Dimension>;
 
  using FileReaderType = itk::ImageFileReader<InputImageType>;
  FileReaderType::Pointer reader = FileReaderType::New();
  reader->SetFileName(argv[1]);
 
  using GradientMagnitudeImageFilterType = itk::GradientMagnitudeImageFilter<InputImageType, FloatImageType>;
  GradientMagnitudeImageFilterType::Pointer gradientMagnitudeImageFilter = GradientMagnitudeImageFilterType::New();
 
  gradientMagnitudeImageFilter->SetInput(reader->GetOutput());
  gradientMagnitudeImageFilter->Update();
 
  using WatershedFilterType = itk::WatershedImageFilter<FloatImageType>;
  WatershedFilterType::Pointer watershed = WatershedFilterType::New();
 
  float threshold = std::stod(argv[3]);
  float level = std::stod(argv[4]);
 
  watershed->SetThreshold(threshold);
  watershed->SetLevel(level);
 
  watershed->SetInput(gradientMagnitudeImageFilter->GetOutput());
  watershed->Update();
 
  using RGBFilterType = itk::ScalarToRGBColormapImageFilter<LabeledImageType, RGBImageType>;
  RGBFilterType::Pointer colormapImageFilter = RGBFilterType::New();
  colormapImageFilter->SetColormap(itk::ScalarToRGBColormapImageFilterEnums::RGBColormapFilter::Jet);
  colormapImageFilter->SetInput(watershed->GetOutput());
  colormapImageFilter->Update();
 
  using FileWriterType = itk::ImageFileWriter<RGBImageType>;
  FileWriterType::Pointer writer = FileWriterType::New();
  writer->SetFileName(argv[2]);
  writer->SetInput(colormapImageFilter->GetOutput());
  writer->Update();
 
  return EXIT_SUCCESS;
}