Apply A Filter Only To A Specified Region Of An Image

Synopsis

Computes the derivative of an image in a particular direction.

Results

Warning

Fix Errors Example contains errors needed to be fixed for proper output.

Code

C++

#include "itkImage.h"
#include "itkImageFileReader.h"
#include "itkDerivativeImageFilter.h"

#ifdef ENABLE_QUICKVIEW
#  include "QuickView.h"
#endif

int
main(int argc, char * argv[])
{
  // Verify command line arguments
  if (argc < 2)
  {
    std::cerr << "Usage: " << std::endl;
    std::cerr << argv[0] << " inputImageFile" << std::endl;
    return EXIT_FAILURE;
  }

  // Parse command line arguments
  std::string inputFilename = argv[1];

  // Setup types
  using FloatImageType = itk::Image<float, 2>;
  using UnsignedCharImageType = itk::Image<unsigned char, 2>;

  using readerType = itk::ImageFileReader<UnsignedCharImageType>;

  using filterType = itk::DerivativeImageFilter<UnsignedCharImageType, FloatImageType>;

  // Create and setup a reader
  readerType::Pointer reader = readerType::New();
  reader->SetFileName(inputFilename.c_str());

  // Create and setup a derivative filter
  filterType::Pointer derivativeFilter = filterType::New();
  derivativeFilter->SetInput(reader->GetOutput());
  derivativeFilter->SetDirection(0); // "x" axis

#ifdef ENABLE_QUICKVIEW
  QuickView viewer;

  viewer.AddImage<UnsignedCharImageType>(reader->GetOutput());
  viewer.AddImage<FloatImageType>(derivativeFilter->GetOutput());
  viewer.Visualize();
#endif

  return EXIT_SUCCESS;
}

Classes demonstrated