SphinxExamples/src/Filtering/ImageLabel/LabelContoursOfConnectComponent/Code.cxx

/*=========================================================================
 *
 *  Copyright NumFOCUS
 *
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *         https://www.apache.org/licenses/LICENSE-2.0.txt
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 *
 *=========================================================================*/
#include "itkImage.h"
#include "itkImageFileReader.h"
#include "itkLabelContourImageFilter.h"
#include "itkConnectedComponentImageFilter.h"
#include "itkScalarToRGBColormapImageFilter.h"
 
#include "itksys/SystemTools.hxx"
#include <sstream>
 
#ifdef ENABLE_QUICKVIEW
#  include "QuickView.h"
#endif
 
namespace
{
using PixelType = unsigned char;
using RGBPixelType = itk::RGBPixel<unsigned char>;
using ImageType = itk::Image<PixelType, 2>;
using RGBImageType = itk::Image<RGBPixelType, 2>;
} // namespace
 
static void
CreateImage(ImageType::Pointer image);
 
int
main(int argc, char * argv[])
{
  // Create or read an image
  ImageType::Pointer image;
  if (argc < 2)
  {
    image = ImageType::New();
    CreateImage(image.GetPointer());
  }
  else
  {
    image = itk::ReadImage<ImageType>(argv[1]);
  }
 
  // Generate connected components
  using ConnectedComponentImageFilterType = itk::ConnectedComponentImageFilter<ImageType, ImageType>;
  auto connectedComponentImageFilter = ConnectedComponentImageFilterType::New();
  connectedComponentImageFilter->SetInput(image);
 
  // Generate contours for each component
  using LabelContourImageFilterType = itk::LabelContourImageFilter<ImageType, ImageType>;
  auto labelContourImageFilter = LabelContourImageFilterType::New();
  labelContourImageFilter->SetInput(connectedComponentImageFilter->GetOutput());
 
  using RGBFilterType = itk::ScalarToRGBColormapImageFilter<ImageType, RGBImageType>;
  auto rgbFilter = RGBFilterType::New();
  rgbFilter->SetInput(labelContourImageFilter->GetOutput());
  rgbFilter->SetColormap(itk::ScalarToRGBColormapImageFilterEnums::RGBColormapFilter::Jet);
 
#ifdef ENABLE_QUICKVIEW
  QuickView viewer;
  viewer.AddImage(
    image.GetPointer(), true, argc > 1 ? itksys::SystemTools::GetFilenameName(argv[1]) : "Generated image");
 
  std::stringstream desc;
  desc << "LabelContourImageFilter";
  viewer.AddRGBImage(rgbFilter->GetOutput(), true, desc.str());
 
  viewer.Visualize();
#endif
  return EXIT_SUCCESS;
}
 
void
CreateImage(ImageType::Pointer image)
{
  // Create an image with 2 connected components
  ImageType::RegionType region;
  ImageType::IndexType  start;
  start[0] = 0;
  start[1] = 0;
 
  ImageType::SizeType size;
  unsigned int        NumRows = 200;
  unsigned int        NumCols = 300;
  size[0] = NumRows;
  size[1] = NumCols;
 
  region.SetSize(size);
  region.SetIndex(start);
 
  image->SetRegions(region);
  image->Allocate();
 
  // Make a square
  for (unsigned int r = 20; r < 80; ++r)
  {
    for (unsigned int c = 30; c < 100; ++c)
    {
      ImageType::IndexType pixelIndex;
      pixelIndex[0] = r;
      pixelIndex[1] = c;
 
      image->SetPixel(pixelIndex, 255);
    }
  }
 
  // Make another square
  for (unsigned int r = 100; r < 130; ++r)
  {
    for (unsigned int c = 115; c < 160; ++c)
    {
      ImageType::IndexType pixelIndex;
      pixelIndex[0] = r;
      pixelIndex[1] = c;
 
      image->SetPixel(pixelIndex, 255);
    }
  }
}