SphinxExamples/src/Filtering/ImageGrid/ResampleAnImage/Code.cxx

#include "itkImageFileReader.h"
#include "itkImageFileWriter.h"
#include "itkLinearInterpolateImageFunction.h"
#include "itkResampleImageFilter.h"
#include "itkScaleTransform.h"

int main( int argc, char* argv[] )
{
  if( argc != 4 )
    {
    std::cerr << "Usage: "<< std::endl;
    std::cerr << argv[0];
    std::cerr << " <InputFileName> <OutputFileName>";
    std::cerr << " <numberOfIterations> <timeStep> <conductance>";
    std::cerr << std::endl;
    return EXIT_FAILURE;
    }

  const char * inputFileName = argv[1];
  const char * outputFileName = argv[2];
  const float scale = atof( argv[3] );

  const unsigned int Dimension = 2;

  typedef unsigned char                       PixelType;
  typedef itk::Image< PixelType, Dimension >  ImageType;
  typedef double                              ScalarType;

  typedef itk::ImageFileReader< ImageType >  ReaderType;
  ReaderType::Pointer reader = ReaderType::New();
  reader->SetFileName( inputFileName );
  reader->Update();

  ImageType::Pointer inputImage = reader->GetOutput();

  ImageType::RegionType region = inputImage->GetLargestPossibleRegion();
  ImageType::SizeType size = region.GetSize();
  ImageType::SpacingType spacing = inputImage->GetSpacing();

  itk::Index< Dimension > centralPixel;
  centralPixel[0] = size[0] / 2;
  centralPixel[1] = size[1] / 2;
  itk::Point< ScalarType, Dimension > centralPoint;
  centralPoint[0] = centralPixel[0];
  centralPoint[1] = centralPixel[1];

  typedef itk::ScaleTransform< ScalarType, Dimension > ScaleTransformType;
  ScaleTransformType::Pointer scaleTransform = ScaleTransformType::New();

  ScaleTransformType::ParametersType parameters = scaleTransform->GetParameters();
  parameters[0] = scale;
  parameters[1] = scale;

  scaleTransform->SetParameters( parameters );
  scaleTransform->SetCenter( centralPoint );

  typedef itk::LinearInterpolateImageFunction< ImageType, ScalarType > LinearInterpolatorType;
  LinearInterpolatorType::Pointer interpolator = LinearInterpolatorType::New();

  typedef itk::ResampleImageFilter< ImageType, ImageType > ResampleFilterType;
  ResampleFilterType::Pointer resampleFilter = ResampleFilterType::New();

  resampleFilter->SetInput( inputImage );
  resampleFilter->SetTransform( scaleTransform );
  resampleFilter->SetInterpolator( interpolator );
  resampleFilter->SetSize( size );
  resampleFilter->SetOutputSpacing( spacing );

  typedef itk::ImageFileWriter< ImageType > WriterType;
  WriterType::Pointer writer = WriterType::New();
  writer->SetFileName( outputFileName );
  writer->SetInput( resampleFilter->GetOutput() );

  try
    {
    writer->Update();
    }
  catch( itk::ExceptionObject & error )
    {
    std::cerr << "Error: " << error << std::endl;
    return EXIT_FAILURE;
    }

  return EXIT_SUCCESS;
}