SphinxExamples/src/Registration/Common/MatchFeaturePoints/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 "itkBlockMatchingImageFilter.h"
#include "itkImage.h"
#include "itkPoint.h"
#include "itkPointSet.h"
 
using ImageType = itk::Image<unsigned char, 2>;
 
static void
CreateImage(ImageType::Pointer image, const unsigned int x);
 
int
main(int /*argc*/, char * /*argv*/[])
{
  // Create input images
  auto fixedImage = ImageType::New();
  CreateImage(fixedImage, 40);
 
  auto movingImage = ImageType::New();
  CreateImage(movingImage, 50);
 
  //  using BlockMatchingImageFilterType = itk::BlockMatchingImageFilter<ImageType, ImageType, PointSetType>;
  using BlockMatchingImageFilterType = itk::BlockMatchingImageFilter<ImageType>;
  auto blockMatchingImageFilter = BlockMatchingImageFilterType::New();
 
  // Generate feature points
  //  using PointSetType = itk::PointSet< float, 2>;
  using PointSetType = BlockMatchingImageFilterType::FeaturePointsType;
  using PointType = PointSetType::PointType;
  using PointsContainerPointer = PointSetType::PointsContainerPointer;
 
  auto                   pointSet = PointSetType::New();
  PointsContainerPointer points = pointSet->GetPoints();
 
  PointType p0, p1, p2, p3;
 
  p0[0] = 40.0;
  p0[1] = 40.0;
  p1[0] = 40.0;
  p1[1] = 60.0;
  p2[0] = 60.0;
  p2[1] = 40.0;
  p3[0] = 60.0;
  p2[1] = 60.0;
 
  points->InsertElement(0, p0);
  points->InsertElement(1, p1);
  points->InsertElement(2, p2);
  points->InsertElement(3, p3);
 
  blockMatchingImageFilter->SetFixedImage(fixedImage);
  blockMatchingImageFilter->SetMovingImage(movingImage);
  blockMatchingImageFilter->SetFeaturePoints(pointSet);
  blockMatchingImageFilter->UpdateLargestPossibleRegion();
 
  typename BlockMatchingImageFilterType::DisplacementsType * displacements =
    blockMatchingImageFilter->GetDisplacements();
 
  std::cout << "There are " << displacements->GetNumberOfPoints() << " displacements." << std::endl;
 
  return EXIT_SUCCESS;
}
 
void
CreateImage(ImageType::Pointer image, const unsigned int x)
{
  // Allocate empty image
  itk::Index<2>         start{};
  auto                  size = itk::Size<2>::Filled(100);
  ImageType::RegionType region(start, size);
  image->SetRegions(region);
  image->Allocate();
  image->FillBuffer(0);
 
  // Make a white square
  for (unsigned int r = x; r < x + 20; ++r)
  {
    for (unsigned int c = 40; c < 60; ++c)
    {
      ImageType::IndexType pixelIndex;
      pixelIndex[0] = r;
      pixelIndex[1] = c;
      image->SetPixel(pixelIndex, 255);
    }
  }
}