text: 
  #include "antsUtilities.h"
  #include <algorithm>
  
  #include "itkImageFileReader.h"
  #include "itkImageFileWriter.h"
  
  #include "itkImageRegionIteratorWithIndex.h"
  
  #include <string>
  #include <vector>
  
  namespace ants
  {
  
  template <unsigned int ImageDimension>
  int PasteImageIntoImage( unsigned int argc, char *argv[] )
  {
    typedef float                                 PixelType;
    typedef itk::Image<PixelType, ImageDimension> ImageType;
  
    std::vector<unsigned int> startIndex =
      ConvertVector<unsigned int>( std::string( argv[5] ) );
  
    typedef itk::ImageFileReader<ImageType> ReaderType;
    typename ReaderType::Pointer reader1 = ReaderType::New();
    reader1->SetFileName( argv[2] );
    reader1->Update();
  
    typename ReaderType::Pointer reader2 = ReaderType::New();
    reader2->SetFileName( argv[3] );
    reader2->Update();
  
    PixelType backgroundValue = 0;
    if( argc > 6 )
      {
      backgroundValue = static_cast<PixelType>( atof( argv[6] ) );
      }
    unsigned int writeOver = 1;
    if( argc > 7 )
      {
      writeOver = static_cast<unsigned int>( std::stoi( argv[7] ) );
      }
    PixelType conflictLabel = -1;
    if( argc > 8 )
      {
      conflictLabel = static_cast<PixelType>( atof( argv[8] ) );
      }
  
    itk::ImageRegionIteratorWithIndex<ImageType> It(
      reader2->GetOutput(), reader2->GetOutput()->GetLargestPossibleRegion() );
    for( It.GoToBegin(); !It.IsAtEnd(); ++It )
      {
      typename ImageType::IndexType index = It.GetIndex();
      PixelType paintValue = It.Get();
      for( unsigned int d = 0; d < ImageDimension; d++ )
        {
        index[d] += startIndex[d];
        }
      if( paintValue != backgroundValue )
        {
        if( reader1->GetOutput()->GetLargestPossibleRegion().IsInside( index ) )
          {
          PixelType canvasValue = reader1->GetOutput()->GetPixel( index );
          if( canvasValue == backgroundValue || writeOver == 1 )
            {
            reader1->GetOutput()->SetPixel( index, paintValue );
            }
          else if( canvasValue != backgroundValue && writeOver == 0 )
            {
            continue;
            }
          else
            {
            reader1->GetOutput()->SetPixel( index, conflictLabel );
            }
          }
        }
      }
  
    typedef itk::ImageFileWriter<ImageType> WriterType;
    typename WriterType::Pointer writer = WriterType::New();
    writer->SetFileName( argv[4] );
    writer->SetInput( reader1->GetOutput() );
    writer->Update();
  
    return EXIT_SUCCESS;
  }
  
  // entry point for the library; parameter 'args' is equivalent to 'argv' in (argc,argv) of commandline parameters to
  // 'main()'
  int PasteImageIntoImage( std::vector<std::string> args, std::ostream* /*out_stream = nullptr */ )
  {
    // put the arguments coming in as 'args' into standard (argc,argv) format;
    // 'args' doesn't have the command name as first, argument, so add it manually;
    // 'args' may have adjacent arguments concatenated into one argument,
    // which the parser should handle
    args.insert( args.begin(), "PasteImageIntoImage" );
  
    int     argc = args.size();
    char* * argv = new char *[args.size() + 1];
    for( unsigned int i = 0; i < args.size(); ++i )
      {
      // allocate space for the string plus a null character
      argv[i] = new char[args[i].length() + 1];
      std::strncpy( argv[i], args[i].c_str(), args[i].length() );
      // place the null character in the end
      argv[i][args[i].length()] = '\0';
      }
    argv[argc] = nullptr;
    // class to automatically cleanup argv upon destruction
    class Cleanup_argv
    {
  public:
      Cleanup_argv( char* * argv_, int argc_plus_one_ ) : argv( argv_ ), argc_plus_one( argc_plus_one_ )
      {
      }
  
      ~Cleanup_argv()
      {
        for( unsigned int i = 0; i < argc_plus_one; ++i )
          {
          delete[] argv[i];
          }
        delete[] argv;
      }
  
  private:
      char* *      argv;
      unsigned int argc_plus_one;
    };
    Cleanup_argv cleanup_argv( argv, argc + 1 );
  
    // antscout->set_stream( out_stream );
  
    if( argc < 6 )
      {
      std::cout << argv[0] << " imageDimension inputCanvasImage inputImage "
               << "outputImage startIndex [backgroundLabel=0] [paintOverNonBackgroundVoxels=0] [conflictLabel=-1]"
               << std::endl;
      std::cout
        <<
        "   If the current painting image voxel is nonbackground and corresponds to a background voxel in the canvas image "
        << std::endl;
      std::cout << "     paintOverNonBackgroundVoxels = 0 -> leave the canvas voxel as is." << std::endl;
      std::cout
        << "     paintOverNonBackgroundVoxels = 1 -> replace canvas voxel value with painting image voxel value"
        << std::endl;
      std::cout << "     paintOverNonBackgroundVoxels = 2 -> replace canvas voxel walue with conflictLabel"  << std::endl;
  
      if( argc >= 2 &&
          ( std::string( argv[1] ) == std::string("--help") || std::string( argv[1] ) == std::string("-h") ) )
        {
        return EXIT_SUCCESS;
        }
      return EXIT_FAILURE;
      }
  
    switch( std::stoi( argv[1] ) )
      {
      case 2:
        {
        return PasteImageIntoImage<2>( argc, argv );
        }
        break;
      case 3:
        {
        return PasteImageIntoImage<3>( argc, argv );
        }
        break;
      case 4:
        {
        return PasteImageIntoImage<4>( argc, argv );
        }
        break;
      default:
        std::cout << "Unsupported dimension" << std::endl;
        return EXIT_FAILURE;
      }
    return EXIT_SUCCESS;
  }
  } // namespace ants
  