/*
 * 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 otbNAPCAImageFilter_h
#define otbNAPCAImageFilter_h

#include "otbMNFImageFilter.h"

namespace otb
{

/** \class NAPCAImageFilter
 * \brief Performs a Noise Adjusted PCA analysis of a vector image.
 *
 * The internal structure of this filter is a filter-to-filter like structure.
 * The estimation of the covariance matrix has persistent capabilities...
 *
 * The high pass filter which has to be used for the noise estimation is templated
 * for a better scalability...
 *
 * This class is very similar to the MNFImageFilter one since only the projection
 * matrix definition (through GenerateTransformationMatrix function)
 * differs.
 *
 * TODO? Use a 2nd input to give a noise image directly?
 *
 * \sa otbStreamingStatisticsVectorImageFilter
 * \sa MNFImageFilter
 *
 * \ingroup OTBDimensionalityReduction
 */
template <class TInputImage, class TOutputImage, class TNoiseImageFilter, Transform::TransformDirection TDirectionOfTransformation>
class ITK_EXPORT NAPCAImageFilter : public MNFImageFilter<TInputImage, TOutputImage, TNoiseImageFilter, TDirectionOfTransformation>
{
public:
  typedef NAPCAImageFilter Self;
  typedef MNFImageFilter<TInputImage, TOutputImage, TNoiseImageFilter, TDirectionOfTransformation> Superclass;
  typedef itk::SmartPointer<Self>       Pointer;
  typedef itk::SmartPointer<const Self> ConstPointer;

  /** Type macro */
  itkNewMacro(Self);

  /** Creation through object factory macro */
  itkTypeMacro(NAPCAImageFilter, MNFImageFilter);

  /** Template parameters typedefs */
  typedef typename Superclass::InputImageType  InputImageType;
  typedef typename Superclass::OutputImageType OutputImageType;

  typedef typename Superclass::CovarianceEstimatorFilterType        CovarianceEstimatorFilterType;
  typedef typename Superclass::CovarianceEstimatorFilterPointerType CovarianceEstimatorFilterPointerType;

  typedef typename Superclass::RealType           RealType;
  typedef typename Superclass::VectorType         VectorType;
  typedef typename Superclass::MatrixObjectType   MatrixObjectType;
  typedef typename Superclass::MatrixType         MatrixType;
  typedef typename Superclass::InternalMatrixType InternalMatrixType;
  typedef typename Superclass::MatrixElementType  MatrixElementType;

  typedef typename Superclass::TransformFilterType        TransformFilterType;
  typedef typename Superclass::TransformFilterPointerType TransformFilterPointerType;

  typedef typename Superclass::NoiseImageFilterType        NoiseImageFilterType;
  typedef typename Superclass::NoiseImageFilterPointerType NoiseImageFilterPointerType;

  typedef typename Superclass::NormalizeFilterType        NormalizeFilterType;
  typedef typename Superclass::NormalizeFilterPointerType NormalizeFilterPointerType;

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

  /** Specific functionality of NAPCA */
  void GenerateTransformationMatrix() override;
}; // end of class

} // end of namespace otb

#ifndef OTB_MANUAL_INSTANTIATION
#include "otbNAPCAImageFilter.hxx"
#endif

#endif
