Examples/Filtering/AntiAliasBinaryImageFilter.cxx

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 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with 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

  ReaderType::Pointer reader = ReaderType::New();

  CastToRealFilterType::Pointer toReal = CastToRealFilterType::New();
  RescaleFilter::Pointer rescale = RescaleFilter::New();

  //Setting the ITK pipeline filter

  // Software Guide : BeginCodeSnippet
  AntiAliasFilterType::Pointer 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 );

  RealWriterType::Pointer realWriter = RealWriterType::New();
  realWriter->SetInput( antiAliasFilter->GetOutput() );
  realWriter->SetFileName( outputFilename1 );

  try
    {
    realWriter->Update();
    }
  catch( itk::ExceptionObject & err )
    {
    std::cout << "ExceptionObject caught !" << std::endl;
    std::cout << err << std::endl;
    return EXIT_FAILURE;
    }


  WriterType::Pointer rescaledWriter = WriterType::New();
  rescale->SetInput( antiAliasFilter->GetOutput() );
  rescaledWriter->SetInput( rescale->GetOutput() );
  rescaledWriter->SetFileName( outputFilename2 );
  try
    {
    rescaledWriter->Update();
    }
  catch( 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;

}