/*
 * Copyright (C) 2005-2020 Centre National d'Etudes Spatiales (CNES)
 *
 * This file is part of Orfeo Toolbox
 *
 *     https://www.orfeo-toolbox.org/
 *
 * 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
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * 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.
 */

#ifndef otbLHMIChangeDetector_h
#define otbLHMIChangeDetector_h

#include "otbBinaryFunctorNeighborhoodImageFilter.h"
#include "otbLHMI.h"

namespace otb
{

/** \class LHMIChangeDetector
 * \brief Implements neighborhood-wise the computation of the
 * cumulant-based approximation to mutual information.
 *
 * This filter is parametrized over the types of the two
 * input images and the type of the output image.
 *
 * Numeric conversions (castings) are done by the C++ defaults.
 *
 * The filter will walk over all the pixels in the two input images, and for
 * each one of them it will do the following:
 *
 * - cast the input 1 pixel value to \c double
 * - cast the input 2 pixel value to \c double
 * - compute the difference of the two pixel values
 * - compute the value of the LHMI
 * - cast the \c double value resulting to the pixel type of the output image
 * - store the casted value into the output image.
 *
 * The filter expect all images to have the same dimension
 * (e.g. all 2D, or all 3D, or all ND)
 *
 * \ingroup IntensityImageFilters Multithreaded
 *
 * \ingroup OTBChangeDetection
 */

template <class TInputImage1, class TInputImage2, class TOutputImage>
class ITK_EXPORT LHMIChangeDetector
    : public BinaryFunctorNeighborhoodImageFilter<TInputImage1, TInputImage2, TOutputImage,
                                                  Functor::LHMI<typename itk::ConstNeighborhoodIterator<TInputImage1>,
                                                                typename itk::ConstNeighborhoodIterator<TInputImage2>, typename TOutputImage::PixelType>>
{
public:
  /** Standard class typedefs. */
  typedef LHMIChangeDetector Self;
  typedef BinaryFunctorNeighborhoodImageFilter<TInputImage1, TInputImage2, TOutputImage,
                                               Functor::LHMI<typename itk::ConstNeighborhoodIterator<TInputImage1>,
                                                             typename itk::ConstNeighborhoodIterator<TInputImage2>, typename TOutputImage::PixelType>>
                                        Superclass;
  typedef itk::SmartPointer<Self>       Pointer;
  typedef itk::SmartPointer<const Self> ConstPointer;

  /** Method for creation through the object factory. */
  itkNewMacro(Self);

  /** Macro defining the type*/
  itkTypeMacro(LHMIChangeDetector, SuperClass);

protected:
  LHMIChangeDetector()
  {
  }
  ~LHMIChangeDetector() override
  {
  }

private:
  LHMIChangeDetector(const Self&) = delete;
  void operator=(const Self&) = delete;
};

} // end namespace otb

#endif
