/*=========================================================================
 *
 *  Copyright UMC Utrecht and contributors
 *
 *  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.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.
 *
 *=========================================================================*/
/*=========================================================================

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkMultiOrderBSplineDecompositionImageFilter.h,v $
  Date:      $Date: 2010-03-19 07:06:01 $
  Version:   $Revision: 1.12 $

  Copyright (c) Insight Software Consortium. All rights reserved.
  See ITKCopyright.txt or http://www.itk.org/HTML/Copyright.htm for details.

  Portions of this code are covered under the VTK copyright.
  See VTKCopyright.txt or http://www.kitware.com/VTKCopyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
     PURPOSE.  See the above copyright notices for more information.

=========================================================================*/
#ifndef itkMultiOrderBSplineDecompositionImageFilter_h
#define itkMultiOrderBSplineDecompositionImageFilter_h

#include <vector>

#include "itkImageLinearIteratorWithIndex.h"
#include <vnl/vnl_matrix.h>

#include "itkImageToImageFilter.h"

namespace itk
{
/** \class MultiOrderBSplineDecompositionImageFilter
 * \brief Calculates the B-Spline coefficients of an image.
 *        Spline order may be per dimension from 0 to 5 per.
 *
 * This class defines N-Dimension B-Spline transformation.
 * It is based on:
 *    [1] M. Unser,
 *       "Splines: A Perfect Fit for Signal and Image Processing,"
 *        IEEE Signal Processing Magazine, vol. 16, no. 6, pp. 22-38,
 *        November 1999.
 *    [2] M. Unser, A. Aldroubi and M. Eden,
 *        "B-Spline Signal Processing: Part I--Theory,"
 *        IEEE Transactions on Signal Processing, vol. 41, no. 2, pp. 821-832,
 *        February 1993.
 *    [3] M. Unser, A. Aldroubi and M. Eden,
 *        "B-Spline Signal Processing: Part II--Efficient Design and Applications,"
 *        IEEE Transactions on Signal Processing, vol. 41, no. 2, pp. 834-848,
 *        February 1993.
 * And code obtained from bigwww.epfl.ch by Philippe Thevenaz
 *
 * Limitations:  Spline order must be between 0 and 5.
 *               Spline order must be set before setting the image.
 *               Uses mirror boundary conditions.
 *               Can only process LargestPossibleRegion
 *
 * \sa itkBSplineInterpolateImageFunction
 *
 *  ***TODO: Is this an ImageFilter?  or does it belong to another group?
 * \ingroup ImageFilters
 * \ingroup SingleThreaded
 * \ingroup CannotBeStreamed
 */
template <typename TInputImage, typename TOutputImage>
class ITK_TEMPLATE_EXPORT MultiOrderBSplineDecompositionImageFilter
  : public ImageToImageFilter<TInputImage, TOutputImage>
{
public:
  ITK_DISALLOW_COPY_AND_MOVE(MultiOrderBSplineDecompositionImageFilter);

  /** Standard class typedefs. */
  using Self = MultiOrderBSplineDecompositionImageFilter;
  using Superclass = ImageToImageFilter<TInputImage, TOutputImage>;
  using Pointer = SmartPointer<Self>;
  using ConstPointer = SmartPointer<const Self>;

  /** Run-time type information (and related methods). */
  itkOverrideGetNameOfClassMacro(MultiOrderBSplineDecompositionImageFilter);

  /** New macro for creation of through a Smart Pointer */
  itkNewMacro(Self);

  /** Inherit input and output image types from Superclass. */
  using typename Superclass::InputImageType;
  using typename Superclass::InputImagePointer;
  using typename Superclass::InputImageConstPointer;
  using typename Superclass::OutputImagePointer;

  using CoeffType = typename itk::NumericTraits<typename TOutputImage::PixelType>::RealType;

  /** Dimension underlying input image. */
  itkStaticConstMacro(ImageDimension, unsigned int, TInputImage::ImageDimension);
  itkStaticConstMacro(OutputImageDimension, unsigned int, TOutputImage::ImageDimension);

  /** Iterator typedef support */
  using OutputLinearIterator = ImageLinearIteratorWithIndex<TOutputImage>;

  /** Get/Sets the Spline Order, supports 0th - 5th order splines. The default
   *  is a 3rd order spline. */
  void
  SetSplineOrder(unsigned int order);

  void
  SetSplineOrder(unsigned int dimension, unsigned int order);

  void
  GetSplineOrder(unsigned int dimension)
  {
    return m_SplineOrder[dimension];
  }


#ifdef ITK_USE_CONCEPT_CHECKING
  /** Begin concept checking */
  itkConceptMacro(DimensionCheck, (Concept::SameDimension<ImageDimension, OutputImageDimension>));
  itkConceptMacro(InputConvertibleToOutputCheck,
                  (Concept::Convertible<typename TInputImage::PixelType, typename TOutputImage::PixelType>));
  itkConceptMacro(DoubleConvertibleToOutputCheck, (Concept::Convertible<double, typename TOutputImage::PixelType>));
  /** End concept checking */
#endif

protected:
  MultiOrderBSplineDecompositionImageFilter();
  ~MultiOrderBSplineDecompositionImageFilter() override = default;
  void
  PrintSelf(std::ostream & os, Indent indent) const override;

  void
  GenerateData() override;

  /** This filter requires all of the input image. */
  void
  GenerateInputRequestedRegion() override;

  /** This filter must produce all of its output at once. */
  void
  EnlargeOutputRequestedRegion(DataObject * output) override;

  /** These are needed by the smoothing spline routine. */
  std::vector<CoeffType>         m_Scratch{};    // temp storage for processing of Coefficients
  typename TInputImage::SizeType m_DataLength{}; // Image size

  unsigned int
         m_SplineOrder[ImageDimension]{}; // User specified spline order per dimension (3rd or cubic is the default)
  double m_SplinePoles[3]{};              // Poles calculated for a given spline order
  int    m_NumberOfPoles{};               // number of poles
  double m_Tolerance{};                   // Tolerance used for determining initial causal coefficient
  unsigned int m_IteratorDirection{};     // Direction for iterator incrementing

private:
  /** Determines the poles for dimension given the Spline Order. */
  virtual void
  SetPoles(unsigned int dimension);

  /** Converts a vector of data to a vector of Spline coefficients. */
  virtual bool
  DataToCoefficients1D();

  /** Converts an N-dimension image of data to an equivalent sized image
   *    of spline coefficients. */
  void
  DataToCoefficientsND();

  /** Determines the first coefficient for the causal filtering of the data. */
  virtual void
  SetInitialCausalCoefficient(double z);

  /** Determines the first coefficient for the anti-causal filtering of the data. */
  virtual void
  SetInitialAntiCausalCoefficient(double z);

  /** Used to initialize the Coefficients image before calculation. */
  void
  CopyImageToImage();

  /** Copies a vector of data from the Coefficients image to the m_Scratch vector. */
  void
  CopyCoefficientsToScratch(OutputLinearIterator &);

  /** Copies a vector of data from m_Scratch to the Coefficients image. */
  void
  CopyScratchToCoefficients(OutputLinearIterator &);
};

} // namespace itk

#ifndef ITK_MANUAL_INSTANTIATION
#  include "itkMultiOrderBSplineDecompositionImageFilter.hxx"
#endif

#endif
