rtkAdditiveGaussianNoiseImageFilter.h

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/*=========================================================================
 *
 *  Copyright RTK Consortium
 *
 *  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.
 *
 *=========================================================================*/

/*=========================================================================
 *
 *  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 rtkAdditiveGaussianNoiseImageFilter_h
#define rtkAdditiveGaussianNoiseImageFilter_h

#include <itkImageToImageFilter.h>
#include <itkNormalVariateGenerator.h>
#include <itkUnaryFunctorImageFilter.h>

#include "rtkMacro.h"

namespace rtk
{

template <class TPixel>
class ITK_TEMPLATE_EXPORT NormalVariateNoiseFunctor
{
public:
  NormalVariateNoiseFunctor()
  {
    m_Mean = 0.0;
    m_StandardDeviation = 1.0;

    m_Generator = itk::Statistics::NormalVariateGenerator::New();

    this->SetSeed(42);
  }

  float
  GetMean() const
  {
    return m_Mean;
  }

  void
  SetMean(float mean)
  {
    m_Mean = mean;
  }

  float
  GetStandardDeviation() const
  {
    return m_StandardDeviation;
  }

  void
  SetStandardDeviation(float stddev)
  {
    m_StandardDeviation = stddev;
  }

  void
  SetSeed(unsigned long seed)
  {
    m_Generator->Initialize(seed);
  }

  void
  SetOutputMinimum(TPixel min)
  {
    m_OutputMinimum = min;
  }

  void
  SetOutputMaximum(TPixel max)
  {
    m_OutputMaximum = max;
  }

  TPixel
  GetOutputMinimum() const
  {
    return m_OutputMinimum;
  }

  TPixel
  GetOutputMaximum() const
  {
    return m_OutputMaximum;
  }

  TPixel
  operator()(TPixel input)
  {
    // Get the minimum and maximum output values
    static const auto min = static_cast<float>(m_OutputMinimum);
    static const auto max = static_cast<float>(m_OutputMaximum);

    // Compute the output
    float output = static_cast<float>(input) + m_Mean + m_StandardDeviation * m_Generator->GetVariate();

    // Clamp the output value in valid range
    output = (output < min ? min : output);
    output = (output > max ? max : output);

    return static_cast<TPixel>(output);
  }

private:
  TPixel                                           m_OutputMinimum;
  TPixel                                           m_OutputMaximum;
  float                                            m_Mean;
  float                                            m_StandardDeviation;
  itk::Statistics::NormalVariateGenerator::Pointer m_Generator;
};


template <class TInputImage>
class ITK_TEMPLATE_EXPORT AdditiveGaussianNoiseImageFilter : public itk::ImageToImageFilter<TInputImage, TInputImage>
{
public:
  ITK_DISALLOW_COPY_AND_MOVE(AdditiveGaussianNoiseImageFilter);

  using Self = AdditiveGaussianNoiseImageFilter;
  using Superclass = itk::ImageToImageFilter<TInputImage, TInputImage>;
  using Pointer = itk::SmartPointer<Self>;
  using ConstPointer = itk::SmartPointer<const Self>;

  itkNewMacro(Self);

  itkOverrideGetNameOfClassMacro(AdditiveGaussianNoiseImageFilter);

  using OutputImageRegionType = typename Superclass::OutputImageRegionType;
  using OutputImagePointer = typename Superclass::OutputImagePointer;

  using InputImageType = TInputImage;
  using InputImagePointer = typename InputImageType::Pointer;
  using InputImageConstPointer = typename InputImageType::ConstPointer;
  using InputImageRegionType = typename InputImageType::RegionType;
  using InputImagePixelType = typename InputImageType::PixelType;
  using InputPixelType = typename InputImageType::PixelType;

  static constexpr unsigned int InputImageDimension = TInputImage::ImageDimension;

  // virtual void GenerateOutputInformation();

  void
  GenerateData() override;

  // Accessor & Mutator methods

  void
  SetMean(float mean)
  {
    m_NoiseFilter->GetFunctor().SetMean(mean);
    this->Modified();
  }

  float
  GetMean() const
  {
    return m_NoiseFilter->GetFunctor().GetMean();
  }

  void
  SetStandardDeviation(float stddev)
  {
    m_NoiseFilter->GetFunctor().SetStandardDeviation(stddev);
    this->Modified();
  }

  float
  GetStandardDeviation() const
  {
    return m_NoiseFilter->GetFunctor().GetStandardDeviation();
  }

  void
  SetSeed(unsigned long seed)
  {
    m_NoiseFilter->GetFunctor().SetSeed(seed);
    this->Modified();
  }

  void
  SetOutputMinimum(InputImagePixelType min)
  {
    if (min == m_NoiseFilter->GetFunctor().GetOutputMinimum())
    {
      return;
    }
    m_NoiseFilter->GetFunctor().SetOutputMinimum(min);
    this->Modified();
  }

  InputImagePixelType
  GetOutputMinimum()
  {
    return m_NoiseFilter->GetFunctor().GetOutputMinimum();
  }

  void
  SetOutputMaximum(InputImagePixelType max)
  {
    if (max == m_NoiseFilter->GetFunctor().GetOutputMaximum())
    {
      return;
    }
    m_NoiseFilter->GetFunctor().SetOutputMaximum(max);
    this->Modified();
  }

  InputImagePixelType
  GetOutputMaximum()
  {
    return m_NoiseFilter->GetFunctor().GetOutputMaximum();
  }

protected:
  AdditiveGaussianNoiseImageFilter();

  void
  PrintSelf(std::ostream & os, itk::Indent indent) const override;

public:
  using NoiseFilterType = itk::UnaryFunctorImageFilter<InputImageType,
                                                       InputImageType,
                                                       NormalVariateNoiseFunctor<typename InputImageType::PixelType>>;

private:
  typename NoiseFilterType::Pointer m_NoiseFilter;
};

} /* end namespace rtk */

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

#endif /* rtkAdditiveGaussianNoiseImageFilter_h */