SphinxExamples/src/Filtering/ImageFilterBase/CustomOperationToCorrespondingPixelsInTwoImages/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 "itkVectorImage.h"
#include "itkVector.h"
#include "itkVariableLengthVector.h"
#include "itkRigid2DTransform.h"
#include "itkBinaryFunctorImageFilter.h"
 
using ImageType = itk::Image<float, 2>;
static void
CreateImage(ImageType::Pointer image);
 
namespace Functor
{
template <class TPixel>
class MySquaredDifference
{
public:
  MySquaredDifference() = default;
  ~MySquaredDifference() = default;
  bool
  operator!=(const MySquaredDifference &) const
  {
    return false;
  }
 
  bool
  operator==(const MySquaredDifference & other) const
  {
    return !(*this != other);
  }
 
  inline TPixel
  operator()(const TPixel & A, const TPixel & B) const
  {
    const auto   dA = static_cast<double>(A);
    const auto   dB = static_cast<double>(B);
    const double diff = dA - dB;
 
    return static_cast<TPixel>(diff * diff);
  }
};
} // namespace Functor
 
int
main()
{
  auto image1 = ImageType::New();
  CreateImage(image1);
  image1->FillBuffer(2);
 
  auto image2 = ImageType::New();
  CreateImage(image2);
  image2->FillBuffer(5);
 
  using FilterType =
    itk::BinaryFunctorImageFilter<ImageType, ImageType, ImageType, Functor::MySquaredDifference<ImageType::PixelType>>;
 
  auto filter = FilterType::New();
  filter->SetInput1(image1);
  filter->SetInput2(image2);
  filter->Update();
 
  itk::Index<2> pixelIndex;
  pixelIndex.Fill(0);
 
  ImageType::PixelType input1PixelValue = image1->GetPixel(pixelIndex);
  ImageType::PixelType input2PixelValue = image2->GetPixel(pixelIndex);
  ImageType::PixelType outputPixelValue = filter->GetOutput()->GetPixel(pixelIndex);
 
  std::cout << "pixel1 was = " << input1PixelValue << std::endl;
  std::cout << "pixel2 was = " << input2PixelValue << std::endl;
  std::cout << "output is = " << outputPixelValue << std::endl;
 
  return EXIT_SUCCESS;
}
 
void
CreateImage(ImageType::Pointer image)
{
  ImageType::IndexType start;
  start.Fill(0);
 
  ImageType::SizeType size;
  size.Fill(10);
 
  ImageType::RegionType region(start, size);
  image->SetRegions(region);
  image->Allocate();
}