WikiExamples/ImageProcessing/ImageFilterOnARegion.cxx

#include "itkImage.h"
#include "itkImageFileReader.h"
#include "itkMedianImageFilter.h"
#include "itkPasteImageFilter.h"
#include "itkSubtractImageFilter.h"

#include "itksys/SystemTools.hxx"

#include <sstream>

#include "QuickView.h"

int main(int argc, char * argv[])
{
  // Verify command line arguments
  if( argc < 2 )
    {
    std::cerr << "Usage: " << std::endl;
    std::cerr << argv[0] << " InputImageFile [radius]" << std::endl;
    return EXIT_FAILURE;
    }
  std::string inputFilename = argv[1];

  // Setup types
  using ImageType = itk::Image<float, 2 >;
  using ReaderType = itk::ImageFileReader<ImageType>;
  using FilterType = itk::MedianImageFilter<ImageType, ImageType >;
  using SubtractType = itk::SubtractImageFilter<ImageType>;
  using PasteType = itk::PasteImageFilter<ImageType, ImageType >;

  // Create and setup a reader
  ReaderType::Pointer reader = ReaderType::New();
  reader->SetFileName( inputFilename );

  // Create and setup a median filter
  FilterType::Pointer medianFilter = FilterType::New();
  FilterType::InputSizeType radius;
  radius.Fill(2);
  if (argc > 2)
    {
    radius.Fill(atoi(argv[2]));
    }

  reader->Update();

  itk::Size<2> processSize;
  processSize[0] =
    reader->GetOutput()->GetLargestPossibleRegion().GetSize()[0] / 2;
  processSize[1] =
    reader->GetOutput()->GetLargestPossibleRegion().GetSize()[1] / 2;
  
  itk::Index<2> processIndex;
  processIndex[0] = processSize[0] / 2;
  processIndex[1] = processSize[1] / 2;
  
  itk::ImageRegion<2> processRegion(processIndex, processSize);

  medianFilter->SetRadius(radius);
  medianFilter->SetInput( reader->GetOutput() );
  medianFilter->GetOutput()->SetRequestedRegion( processRegion );

  PasteType::Pointer pasteFilter = PasteType::New();

  pasteFilter->SetSourceImage(medianFilter->GetOutput());
  pasteFilter->SetSourceRegion(medianFilter->GetOutput()->GetRequestedRegion());
  pasteFilter->SetDestinationImage(reader->GetOutput());
  pasteFilter->SetDestinationIndex(processIndex);

  SubtractType::Pointer diff = SubtractType::New();
  diff->SetInput1(reader->GetOutput());
  diff->SetInput2(pasteFilter->GetOutput());

  QuickView viewer;
  viewer.AddImage(
    reader->GetOutput(),true,
    itksys::SystemTools::GetFilenameName(inputFilename));  

  std::stringstream desc;
  desc << "Median/PasteImageFilter, radius = " << radius;
  viewer.AddImage(
    pasteFilter->GetOutput(),
    true,
    desc.str());  

  std::stringstream desc2;
  desc2 << "Original - Median/Paste";
  viewer.AddImage(
    diff->GetOutput(),
    true,
    desc2.str());  

  viewer.Visualize();

  return EXIT_SUCCESS;
}