itkClampImageFilter.h

/*=========================================================================
 *
 *  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 itkClampImageFilter_h
#define itkClampImageFilter_h

#include "itkUnaryFunctorImageFilter.h"

namespace itk
{

namespace Functor
{

/**
 * \class Clamp
 *
 * \brief Functor used to clamp a value to a specified range.
 *
 * Default range corresponds to the range supported by the
 * output type.
 *
 * It is templated over an input and an output-type in order
 * to be able to cast the output value.
 *
 * \ingroup ITKImageIntensity
 */
template <typename TInput, typename TOutput = TInput>
class ITK_TEMPLATE_EXPORT Clamp
{
public:
  using Self = Clamp;

  using InputType = TInput;
  using OutputType = TOutput;

  /** Creates the functor and initializes the bounds to the
   * output-type limits.
   */
  Clamp();

  ~Clamp() = default;

  OutputType
  GetLowerBound() const;
  OutputType
  GetUpperBound() const;

  /** Set the bounds of the range in which the data will be clamped.
   * If the lower-bound is greater than the upper-bound,
   * an itk::ExceptionObject will be thrown.
   */
  void
  SetBounds(const OutputType lowerBound, const OutputType upperBound);

  bool
  operator==(const Self & other) const;

  ITK_UNEQUAL_OPERATOR_MEMBER_FUNCTION(Self);

  OutputType
  operator()(const InputType & A) const;

#ifdef ITK_USE_CONCEPT_CHECKING
  itkConceptMacro(InputConvertibleToOutputCheck, (Concept::Convertible<InputType, OutputType>));
  itkConceptMacro(InputConvertibleToDoubleCheck, (Concept::Convertible<InputType, double>));
  itkConceptMacro(DoubleLessThanComparableToOutputCheck, (Concept::LessThanComparable<double, OutputType>));
  itkConceptMacro(DoubleGreaterThanComparableToOutputCheck, (Concept::GreaterThanComparable<double, OutputType>));
#endif

private:
  OutputType m_LowerBound;
  OutputType m_UpperBound;
};


template <typename TInput, typename TOutput>
inline auto
Clamp<TInput, TOutput>::operator()(const InputType & A) const -> OutputType
{
  const auto dA = static_cast<double>(A);

  if (dA < m_LowerBound)
  {
    return m_LowerBound;
  }

  if (dA > m_UpperBound)
  {
    return m_UpperBound;
  }

  return static_cast<OutputType>(A);
}

} // end namespace Functor


/**
 * \class ClampImageFilter
 *
 * \brief Casts input pixels to output pixel type and clamps the
 * output pixel values to a specified range.
 *
 * Default range corresponds to the range supported by the
 * pixel type of the output image.
 *
 * This filter is templated over the input image type
 * and the output image type.
 *
 * \author Gaetan Lehmann. Biologie du Developpement et de la Reproduction, INRA de Jouy-en-Josas, France.
 *
 * \ingroup IntensityImageFilters
 * \ingroup MultiThreaded
 * \ingroup ITKImageIntensity
 *
 * \sa UnaryFunctorImageFilter
 * \sa CastImageFilter
 *
 * \sphinx
 * \sphinxexample{Filtering/ImageIntensity/CastImageToAnotherTypeButClampToOutput,Cast Image To Another Type But Clamp
 * To Output Range} \endsphinx
 */
template <typename TInputImage, typename TOutputImage>
class ITK_TEMPLATE_EXPORT ClampImageFilter
  : public UnaryFunctorImageFilter<TInputImage,
                                   TOutputImage,
                                   Functor::Clamp<typename TInputImage::PixelType, typename TOutputImage::PixelType>>
{
public:
  ITK_DISALLOW_COPY_AND_MOVE(ClampImageFilter);

  /** Standard class type aliases. */
  using Self = ClampImageFilter;
  using Superclass =
    UnaryFunctorImageFilter<TInputImage,
                            TOutputImage,
                            Functor::Clamp<typename TInputImage::PixelType, typename TOutputImage::PixelType>>;

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

  using InputPixelType = typename TInputImage::PixelType;
  using OutputPixelType = typename TOutputImage::PixelType;

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

  /** \see LightObject::GetNameOfClass() */
  itkOverrideGetNameOfClassMacro(ClampImageFilter);

  OutputPixelType
  GetLowerBound() const;
  OutputPixelType
  GetUpperBound() const;

  /** Set the bounds of the range in which the data will be clamped.
   * If the lower-bound is greater than the upper-bound,
   * an itk::ExceptionObject will be thrown.
   */
  void
  SetBounds(const OutputPixelType lowerBound, const OutputPixelType upperBound);

protected:
  ClampImageFilter() = default;
  ~ClampImageFilter() override = default;

  void
  GenerateData() override;

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

} // end namespace itk

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

#endif