WikiExamples/ImageProcessing/ShapeAttributes.cxx

#include "itkImage.h"
#include "itkImageFileReader.h"
#include "itkConnectedComponentImageFilter.h"
#include "itkLabelImageToShapeLabelMapFilter.h"

template <typename TImage>
static void CreateImage(TImage* const image);

int main( int argc, char *argv[])
{
  constexpr unsigned int Dimension = 2;
  using PixelType = unsigned char;
  using LabelType = unsigned short;
  using InputImageType = itk::Image<PixelType, Dimension>;
  using OutputImageType = itk::Image< LabelType, Dimension >;
  using ShapeLabelObjectType = itk::ShapeLabelObject< LabelType, Dimension >;
  using LabelMapType = itk::LabelMap< ShapeLabelObjectType >;

  std::string fileName;
  InputImageType::Pointer image;
  if( argc < 2 )
    {
    image = InputImageType::New();
    CreateImage(image.GetPointer());
    fileName = "Generated image";
    }
  else
    {
    fileName = argv[1];
    using ReaderType = itk::ImageFileReader<InputImageType>;
    ReaderType::Pointer reader = ReaderType::New();
    reader->SetFileName(fileName);
    reader->Update();

    image = reader->GetOutput();
    }


  using ConnectedComponentImageFilterType = itk::ConnectedComponentImageFilter <InputImageType, OutputImageType >;
  using I2LType = itk::LabelImageToShapeLabelMapFilter< OutputImageType, LabelMapType>;

  ConnectedComponentImageFilterType::Pointer connected =
    ConnectedComponentImageFilterType::New ();
  connected->SetInput(image);
  connected->Update();

  using I2LType = itk::LabelImageToShapeLabelMapFilter< OutputImageType, LabelMapType>;
  I2LType::Pointer i2l = I2LType::New();
  i2l->SetInput( connected->GetOutput() );
  i2l->SetComputePerimeter(true);
  i2l->Update();

  LabelMapType *labelMap = i2l->GetOutput();
  std::cout << "File " << "\"" << fileName << "\""
            << " has " << labelMap->GetNumberOfLabelObjects() << " labels." << std::endl;

  // Retrieve all attributes
  for (unsigned int n = 0; n < labelMap->GetNumberOfLabelObjects(); ++n)
    {
    ShapeLabelObjectType *labelObject = labelMap->GetNthLabelObject(n);
    std::cout << "Label: "
              << itk::NumericTraits<LabelMapType::LabelType>::PrintType(labelObject->GetLabel()) << std::endl;
    std::cout << "    BoundingBox: "
              << labelObject->GetBoundingBox() << std::endl;
    std::cout << "    NumberOfPixels: "
              << labelObject->GetNumberOfPixels() << std::endl;
    std::cout << "    PhysicalSize: "
              << labelObject->GetPhysicalSize() << std::endl;
    std::cout << "    Centroid: "
              << labelObject->GetCentroid() << std::endl;
    std::cout << "    NumberOfPixelsOnBorder: "
              << labelObject->GetNumberOfPixelsOnBorder() << std::endl;
    std::cout << "    PerimeterOnBorder: "
              << labelObject->GetPerimeterOnBorder() << std::endl;
    std::cout << "    FeretDiameter: "
              << labelObject->GetFeretDiameter() << std::endl;
    std::cout << "    PrincipalMoments: "
              << labelObject->GetPrincipalMoments() << std::endl;
    std::cout << "    PrincipalAxes: "
              << labelObject->GetPrincipalAxes() << std::endl;
    std::cout << "    Elongation: "
              << labelObject->GetElongation() << std::endl;
    std::cout << "    Perimeter: "
              << labelObject->GetPerimeter() << std::endl;
    std::cout << "    Roundness: "
              << labelObject->GetRoundness() << std::endl;
    std::cout << "    EquivalentSphericalRadius: "
              << labelObject->GetEquivalentSphericalRadius() << std::endl;
    std::cout << "    EquivalentSphericalPerimeter: "
              << labelObject->GetEquivalentSphericalPerimeter() << std::endl;
    std::cout << "    EquivalentEllipsoidDiameter: "
              << labelObject->GetEquivalentEllipsoidDiameter() << std::endl;
    std::cout << "    Flatness: "
              << labelObject->GetFlatness() << std::endl;
    std::cout << "    PerimeterOnBorderRatio: "
              << labelObject->GetPerimeterOnBorderRatio() << std::endl;
    }

  return EXIT_SUCCESS;
}

template <typename TImage>
void CreateImage(TImage* const image)
{
  // Create an image with 2 objects
  typename TImage::IndexType start = {{0,0}};
  start[0] = 0;
  start[1] = 0;

  typename TImage::SizeType size;
  unsigned int NumRows = 200;
  unsigned int NumCols = 300;
  size[0] = NumRows;
  size[1] = NumCols;

  typename TImage::RegionType region(start, size);

  image->SetRegions(region);
  image->Allocate();

  // Make a square
  for(typename TImage::IndexValueType r = 20; r < 80; ++r)
    {
    for(typename TImage::IndexValueType c = 30; c < 100; ++c)
      {
      typename TImage::IndexType pixelIndex = {{r,c}};

      image->SetPixel(pixelIndex, 255);
      }
    }

  // Make another square
  for(typename TImage::IndexValueType r = 100; r < 130; ++r)
    {
    for(typename TImage::IndexValueType c = 115; c < 160; ++c)
      {
      typename TImage::IndexType pixelIndex = {{r,c}};

      image->SetPixel(pixelIndex, 255);
      }
    }
}