Examples/Filtering/AntiAliasBinaryImageFilter.cxx

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 *  Licensed under the Apache License, Version 2.0 (the "License");
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//  Software Guide : BeginLatex
//
//  This example introduces the use of the
//  \doxygen{AntiAliasBinaryImageFilter}. This filter expect a binary mask as
//  input, and using Level Sets it smooths the image by keeping the edge of
//  the structure within 1 pixel distance from the original location. It is
//  usually desirable to run this filter before extracting isocontour with
//  surface extraction methods.
//
//  \index{itk::AntiAliasBinaryImageFilter|textbf}
//
//  Software Guide : EndLatex
 
 
#include "itkImageFileReader.h"
#include "itkImageFileWriter.h"
#include "itkCastImageFilter.h"
#include "itkRescaleIntensityImageFilter.h"
 
 
//  Software Guide : BeginLatex
//
//  The first step required for using this filter is to include its header
//  file
//
//  \index{itk::AntiAliasBinaryImageFilter!header}
//
//  Software Guide : EndLatex
 
 
// Software Guide : BeginCodeSnippet
#include "itkAntiAliasBinaryImageFilter.h"
// Software Guide : EndCodeSnippet
 
 
int
main(int argc, char * argv[])
{
  if (argc < 3)
  {
    std::cerr << "Usage: " << std::endl;
    std::cerr << argv[0] << " inputImage outputImageDoublePixelType ";
    std::cerr << " outputImage8BitsPixelType [RMS] [numberOfIterations]"
              << std::endl;
    return EXIT_FAILURE;
  }
 
  const char * inputFilename = argv[1];
  const char * outputFilename1 = argv[2];
  const char * outputFilename2 = argv[3];
 
  double       maximumRMSError = 0.01;
  unsigned int numberOfIterations = 50;
 
  if (argc > 4)
  {
    maximumRMSError = std::stod(argv[4]);
  }
 
  if (argc > 5)
  {
    numberOfIterations = std::stoi(argv[5]);
  }
 
 
  using CharPixelType = unsigned char; //  IO
  using RealPixelType = double;        //  Operations
  constexpr unsigned int Dimension = 3;
 
  using CharImageType = itk::Image<CharPixelType, Dimension>;
  using RealImageType = itk::Image<RealPixelType, Dimension>;
 
  using ReaderType = itk::ImageFileReader<CharImageType>;
  using WriterType = itk::ImageFileWriter<CharImageType>;
 
  using RealWriterType = itk::ImageFileWriter<RealImageType>;
 
  //  Software Guide : BeginLatex
  //
  //  This filter operates on image of pixel type float. It is then necessary
  //  to cast the type of the input images that are usually of integer type.
  //  The \doxygen{CastImageFilter} is used here for that purpose. Its image
  //  template parameters are defined for casting from the input type to the
  //  float type using for processing.
  //
  //  Software Guide : EndLatex
 
  // Software Guide : BeginCodeSnippet
  using CastToRealFilterType =
    itk::CastImageFilter<CharImageType, RealImageType>;
  // Software Guide : EndCodeSnippet
 
  using RescaleFilter =
    itk::RescaleIntensityImageFilter<RealImageType, CharImageType>;
 
 
  //  Software Guide : BeginLatex
  //
  //  The \doxygen{AntiAliasBinaryImageFilter} is instantiated using the float
  //  image type.
  //
  //  \index{itk::AntiAliasBinaryImageFilter|textbf}
  //
  //  Software Guide : EndLatex
 
 
  using AntiAliasFilterType =
    itk::AntiAliasBinaryImageFilter<RealImageType, RealImageType>;
 
  // Setting the IO
 
  auto reader = ReaderType::New();
 
  auto toReal = CastToRealFilterType::New();
  auto rescale = RescaleFilter::New();
 
  // Setting the ITK pipeline filter
 
  // Software Guide : BeginCodeSnippet
  auto antiAliasFilter = AntiAliasFilterType::New();
 
  reader->SetFileName(inputFilename);
 
  // The output of an edge filter is 0 or 1
  rescale->SetOutputMinimum(0);
  rescale->SetOutputMaximum(255);
 
  toReal->SetInput(reader->GetOutput());
 
  antiAliasFilter->SetInput(toReal->GetOutput());
  antiAliasFilter->SetMaximumRMSError(maximumRMSError);
  antiAliasFilter->SetNumberOfIterations(numberOfIterations);
  antiAliasFilter->SetNumberOfLayers(2);
 
  auto realWriter = RealWriterType::New();
  realWriter->SetInput(antiAliasFilter->GetOutput());
  realWriter->SetFileName(outputFilename1);
 
  try
  {
    realWriter->Update();
  }
  catch (const itk::ExceptionObject & err)
  {
    std::cout << "ExceptionObject caught !" << std::endl;
    std::cout << err << std::endl;
    return EXIT_FAILURE;
  }
 
 
  auto rescaledWriter = WriterType::New();
  rescale->SetInput(antiAliasFilter->GetOutput());
  rescaledWriter->SetInput(rescale->GetOutput());
  rescaledWriter->SetFileName(outputFilename2);
  try
  {
    rescaledWriter->Update();
  }
  catch (const itk::ExceptionObject & err)
  {
    std::cout << "ExceptionObject caught !" << std::endl;
    std::cout << err << std::endl;
    return EXIT_FAILURE;
  }
  std::cout << "Completed in " << antiAliasFilter->GetNumberOfIterations()
            << std::endl;
 
  // Software Guide : EndCodeSnippet
 
  return EXIT_SUCCESS;
}