itkUnsharpMaskImageFilter.h

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/*=========================================================================
 *
 *  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.
 *
 *=========================================================================*/
#ifndef itkUnsharpMaskImageFilter_h
#define itkUnsharpMaskImageFilter_h
 
#include "itkImageToImageFilter.h"
#include "itkSmoothingRecursiveGaussianImageFilter.h"
 
namespace itk
{
 
template <typename TInputImage, typename TOutputImage = TInputImage, typename TInternalPrecision = float>
class ITK_TEMPLATE_EXPORT UnsharpMaskImageFilter : public ImageToImageFilter<TInputImage, TOutputImage>
{
public:
  ITK_DISALLOW_COPY_AND_MOVE(UnsharpMaskImageFilter);

  using Self = UnsharpMaskImageFilter;
  using Superclass = ImageToImageFilter<TInputImage, TOutputImage>;

  using OutputPixelType = typename TOutputImage::PixelType;
  using OutputInternalPixelType = typename TOutputImage::InternalPixelType;
  using InputPixelType = typename TInputImage::PixelType;
  using InputInternalPixelType = typename TInputImage::InternalPixelType;
  using OutputImageRegionType = typename TOutputImage::RegionType;
  using InputImageRegionType = typename TInputImage::RegionType;
  static constexpr unsigned int ImageDimension = TOutputImage::ImageDimension;
  static constexpr unsigned int InputImageDimension = TInputImage::ImageDimension;

  using InputImageType = TInputImage;
  using OutputImageType = TOutputImage;
  using InputImagePointer = typename InputImageType::Pointer;
 
  using InternalPrecisionType = TInternalPrecision;

  using Pointer = SmartPointer<Self>;
  using ConstPointer = SmartPointer<const Self>;

  itkOverrideGetNameOfClassMacro(UnsharpMaskImageFilter);

  itkNewMacro(Self);
 
  itkConceptMacro(SameDimensionCheck, (Concept::SameDimension<InputImageDimension, ImageDimension>));
  itkConceptMacro(InputHasNumericTraitsCheck, (Concept::HasNumericTraits<OutputPixelType>));
  itkConceptMacro(InternalTypeIsFloatingPoint, (Concept::IsFloatingPoint<TInternalPrecision>));
 
  using GaussianType =
    SmoothingRecursiveGaussianImageFilter<TInputImage, Image<TInternalPrecision, TOutputImage::ImageDimension>>;
 
  using SigmaArrayType = typename GaussianType::SigmaArrayType;

  itkSetMacro(Sigmas, SigmaArrayType);
  itkGetConstMacro(Sigmas, SigmaArrayType);

  void
  SetSigma(const typename SigmaArrayType::ValueType sigma)
  {
    auto sigmas = MakeFilled<SigmaArrayType>(sigma);
    this->SetSigmas(sigmas); // checks whether it is actually modified
  }

  itkSetMacro(Amount, TInternalPrecision);
  itkGetConstMacro(Amount, TInternalPrecision);

  itkSetMacro(Threshold, TInternalPrecision);
  itkGetConstMacro(Threshold, TInternalPrecision);

  itkSetMacro(Clamp, bool);
  itkGetConstMacro(Clamp, bool);
  itkBooleanMacro(Clamp);
protected:
  UnsharpMaskImageFilter();
  ~UnsharpMaskImageFilter() override = default;

  void
  GenerateInputRequestedRegion() override;
 
  void
  VerifyPreconditions() const override;
  void
  GenerateData() override;
 
  void
  PrintSelf(std::ostream & os, Indent indent) const override;
 
private:
  TInternalPrecision m_Amount{};
  TInternalPrecision m_Threshold{};
  SigmaArrayType     m_Sigmas{};
  bool               m_Clamp{};
 
  template <typename InPixelType, typename FunctorRealType = TInternalPrecision, typename OutPixelType = InPixelType>
  class UnsharpMaskingFunctor
  {
  private:
    FunctorRealType m_Amount;
    FunctorRealType m_Threshold;
    bool            m_Clamp{ false };
 
  public:
    UnsharpMaskingFunctor()
      : m_Amount(0.5)
      , m_Threshold(0.0)
 
    {}
 
    UnsharpMaskingFunctor(FunctorRealType amount, FunctorRealType threshold, bool clamp)
      : m_Amount(amount)
      , m_Threshold(threshold)
      , m_Clamp(clamp)
    {
      assert(m_Threshold >= 0.0);
    }
 
    bool
    operator==(const UnsharpMaskingFunctor & other) const
    {
      return (m_Amount == other.m_Amount) && (m_Threshold == other.m_Threshold) && (m_Clamp == other.m_Clamp);
    }
 
    ITK_UNEQUAL_OPERATOR_MEMBER_FUNCTION(UnsharpMaskingFunctor);
 
    inline OutPixelType
    operator()(const InPixelType & v, const FunctorRealType & s) const
    {
      FunctorRealType diff = v - s;
      FunctorRealType result;
      if (diff > m_Threshold)
      {
        result = v + (diff - m_Threshold) * m_Amount;
      }
      else if (-diff > m_Threshold)
      {
        result = v + (diff + m_Threshold) * m_Amount;
      }
      else
      {
        result = v;
      }
 
      if (m_Clamp)
      {
        if (result < itk::NumericTraits<OutPixelType>::NonpositiveMin())
        {
          return itk::NumericTraits<OutPixelType>::NonpositiveMin();
        }
        if (result > itk::NumericTraits<OutPixelType>::max())
        {
          return itk::NumericTraits<OutPixelType>::max();
        }
      }
 
      return static_cast<OutPixelType>(result);
    }
  }; // end UnsharpMaskingFunctor
}; // end UnsharpMaskImageFilter
} // end namespace itk
 
#ifndef ITK_MANUAL_INSTANTIATION
#  include "itkUnsharpMaskImageFilter.hxx"
#endif
 
#endif