Iterate Region in Image With Access to Current Index With Write Access

Synopsis

Iterate over a region of an image with efficient access to the current index (with write access).

Results

Yinyang.png

Yinyang.png In VTK Window With Index Access

Output:

Indices:
Index: [0, 0] value: ?
Index: [1, 0] value: ?
Index: [2, 0] value: ?
Index: [3, 0] value: ?
Index: [4, 0] value: ?
Index: [0, 1] value: ?
Index: [1, 1] value: ?
Index: [2, 1] value: ?
Index: [3, 1] value: ?
Index: [4, 1] value: ?
Index: [0, 2] value: ?
Index: [1, 2] value: ?
Index: [2, 2] value: ?
Index: [3, 2] value: ?
Index: [4, 2] value: ?
Index: [0, 3] value: ?
Index: [1, 3] value: ?
Index: [2, 3] value: ?
Index: [3, 3] value: ?
Index: [4, 3] value: ?

Code

C++

#include "itkImage.h"
#include "itkImageFileReader.h"
#include "itkImageRegionIteratorWithIndex.h"

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

int
main(int argc, char * argv[])
{
  if (argc < 2)
  {
    std::cerr << "Required: filename" << std::endl;
    return EXIT_FAILURE;
  }

  using ImageType = itk::Image<unsigned char, 2>;

  using ReaderType = itk::ImageFileReader<ImageType>;
  ReaderType::Pointer reader = ReaderType::New();
  reader->SetFileName(argv[1]);
  reader->Update();

  ImageType::Pointer image = reader->GetOutput();

  ImageType::SizeType regionSize;
  regionSize[0] = 5;
  regionSize[1] = 4;

  ImageType::IndexType regionIndex;
  regionIndex[0] = 0;
  regionIndex[1] = 0;

  ImageType::RegionType region;
  region.SetSize(regionSize);
  region.SetIndex(regionIndex);

  itk::ImageRegionIteratorWithIndex<ImageType> imageIterator(image, region);

  while (!imageIterator.IsAtEnd())
  {
    std::cout << "Index: " << imageIterator.GetIndex() << " value: " << (int)imageIterator.Get() << std::endl;

    // Set the current pixel to white
    imageIterator.Set(255);

    ++imageIterator;
  }

#ifdef ENABLE_QUICKVIEW
  // Visualize
  QuickView viewer;
  viewer.AddImage<ImageType>(image);
  viewer.Visualize();
#endif

  return EXIT_SUCCESS;
}

Classes demonstrated

template<typename TImage>
class ImageRegionIteratorWithIndex : public itk::ImageRegionConstIteratorWithIndex<TImage>

A multi-dimensional iterator templated over image type that walks pixels within a region and is specialized to keep track of its image index location.

This class is a specialization of ImageRegionConstIteratorWithIndex that adds write-access (the Set() method). Please see ImageRegionConstIteratorWithIndex for more information.

MORE INFORMATION

For a complete description of the ITK Image Iterators and their API, please see the Iterators chapter in the ITK Software Guide. The ITK Software Guide is available in print and as a free .pdf download from https://www.itk.org.

See

ImageConstIterator

See

ConditionalConstIterator

See

ConstNeighborhoodIterator

See

ConstShapedNeighborhoodIterator

See

ConstSliceIterator

See

CorrespondenceDataStructureIterator

See

FloodFilledFunctionConditionalConstIterator

See

FloodFilledImageFunctionConditionalConstIterator

See

FloodFilledImageFunctionConditionalIterator

See

FloodFilledSpatialFunctionConditionalConstIterator

See

FloodFilledSpatialFunctionConditionalIterator

See

ImageConstIterator

See

ImageConstIteratorWithIndex

See

ImageIterator

See

ImageIteratorWithIndex

See

ImageLinearConstIteratorWithIndex

See

ImageLinearIteratorWithIndex

See

ImageRandomConstIteratorWithIndex

See

ImageRandomIteratorWithIndex

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ImageRegionConstIterator

See

ImageRegionConstIteratorWithIndex

See

ImageRegionExclusionConstIteratorWithIndex

See

ImageRegionExclusionIteratorWithIndex

See

ImageRegionIterator

See

ImageRegionIteratorWithIndex

See

ImageRegionReverseConstIterator

See

ImageRegionReverseIterator

See

ImageReverseConstIterator

See

ImageReverseIterator

See

ImageSliceConstIteratorWithIndex

See

ImageSliceIteratorWithIndex

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NeighborhoodIterator

See

PathConstIterator

See

PathIterator

See

ShapedNeighborhoodIterator

See

SliceIterator

See

ImageConstIteratorWithIndex

See

ImageRegionRange

See

ImageRegionIndexRange

ITK Sphinx Examples:

• All ITK Sphinx Examples

• Iterate Region In Image With Access To Current Index With Write Access

See itk::ImageRegionIteratorWithIndex for additional documentation.