SphinxExamples/src/Core/Transform/ApplyAffineTransformFromHomogeneousMatrixAndResample/Code.cxx

#include "itkImageFileReader.h"
#include "itkImageFileWriter.h"
#include "itkAffineTransform.h"
#include "itkResampleImageFilter.h"
#include "itkWindowedSincInterpolateImageFunction.h"

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

  const unsigned int Dimension = 2;
  typedef double ScalarType;

  const char * inputFileName = argv[1];
  const char * outputFileName = argv[2];
  const ScalarType defaultValue = static_cast< ScalarType >( atof( argv[3] ) );

  typedef itk::Matrix< ScalarType, Dimension + 1, Dimension + 1 > MatrixType;
  MatrixType matrix;
  matrix[0][0] = std::cos( 0.05 );
  matrix[0][1] = std::sin( 0.05 );
  matrix[0][2] = 0.;

  matrix[1][0] = - matrix[0][1];
  matrix[1][1] = matrix[0][0];
  matrix[1][2] = 0.;

  matrix[2][0] = -10.;
  matrix[2][1] = -20.;
  matrix[2][2] = 1.;

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

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

  ImageType::ConstPointer input = reader->GetOutput();

  const ImageType::SizeType& size = input->GetLargestPossibleRegion().GetSize();

  typedef itk::ResampleImageFilter< ImageType, ImageType > ResampleImageFilterType;
  ResampleImageFilterType::Pointer resample = ResampleImageFilterType::New();
  resample->SetInput( input );
  resample->SetReferenceImage( input );
  resample->UseReferenceImageOn();
  resample->SetSize( size );
  resample->SetDefaultPixelValue( defaultValue );

  const unsigned int Radius = 3;
  typedef itk::WindowedSincInterpolateImageFunction< ImageType, Radius > InterpolatorType;
  InterpolatorType::Pointer interpolator = InterpolatorType::New();

  resample->SetInterpolator( interpolator );

  typedef itk::AffineTransform< ScalarType, Dimension > TransformType;
  TransformType::Pointer transform = TransformType::New();

  // get transform parameters from MatrixType
  TransformType::ParametersType parameters( Dimension * Dimension + Dimension );
  for( unsigned int i = 0; i < Dimension; i++ )
    {
    for( unsigned int j = 0; j < Dimension; j++ )
      {
      parameters[ i * Dimension + j ] = matrix[ i ][ j ];
      }
    }
  for( unsigned int i = 0; i < Dimension; i++ )
    {
    parameters[ i + Dimension * Dimension ] = matrix[ i ][ Dimension ];
    }
  transform->SetParameters( parameters );

  resample->SetTransform( transform );

  typedef itk::ImageFileWriter< ImageType > WriterType;
  WriterType::Pointer writer = WriterType::New();
  writer->SetFileName( outputFileName );
  writer->SetInput( resample->GetOutput() );
  try
    {
    writer->Update();
    }
  catch( itk::ExceptionObject & error )
    {
    std::cerr << "Error: " << error << std::endl;
    return EXIT_FAILURE;
    }

  return EXIT_SUCCESS;
}