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

/*=========================================================================
 *
 *  Copyright Insight Software Consortium
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *         http://www.apache.org/licenses/LICENSE-2.0.txt
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *=========================================================================*/

#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;
    }

  constexpr unsigned int Dimension = 2;
  using ScalarType = double;

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

  using MatrixType = itk::Matrix< ScalarType, Dimension + 1, Dimension + 1 >;
  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.;

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

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

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

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

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

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

  resample->SetInterpolator( interpolator );

  using TransformType = itk::AffineTransform< ScalarType, Dimension >;
  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 );

  using WriterType = itk::ImageFileWriter< ImageType >;
  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;
}