ITK/Examples/ImageProcessing/NthElementImageAdaptor

#include "itkImageAdaptor.h"
#include "itkImageRegionIterator.h"
#include "itkNthElementImageAdaptor.h"
 
typedef itk::Image<itk::CovariantVector< float, 3>, 2> VectorImageType;
 
static void CreateImage(VectorImageType::Pointer image);
 
int main(int, char *[])
{
  VectorImageType::Pointer image = VectorImageType::New();
  CreateImage(image);
 
  itk::Index<2> index;
  index.Fill(0);
 
  std::cout << image->GetPixel(index) << std::endl;
 
  typedef itk::NthElementImageAdaptor<VectorImageType,
    float> ImageAdaptorType;
 
  ImageAdaptorType::Pointer adaptor = ImageAdaptorType::New();
 
  adaptor->SelectNthElement(0);
  adaptor->SetImage(image);
 
  std::cout << adaptor->GetPixel(index) << std::endl;
 
  return EXIT_SUCCESS;
}
 
void CreateImage(VectorImageType::Pointer image)
{
  VectorImageType::IndexType start;
  start.Fill(0);
 
  VectorImageType::SizeType size;
  size.Fill(2);
 
  VectorImageType::RegionType region;
  region.SetSize(size);
  region.SetIndex(start);
 
  image->SetRegions(region);
  image->Allocate();
 
  // Create a pixel and fill it with (1,2,3), and set every pixel of the image to this pixel.
 
  itk::ImageRegionIterator<VectorImageType> imageIterator(image,image->GetLargestPossibleRegion());
  itk::CovariantVector<float, 3> vectorPixel;
  vectorPixel[0] = 1;
  vectorPixel[1] = 2;
  vectorPixel[2] = 3;
 
  image->FillBuffer(vectorPixel);
}