itkImageFunction.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 itkImageFunction_h
#define itkImageFunction_h
 
#include "itkFunctionBase.h"
#include "itkIndex.h"
#include "itkImageBase.h"
 
namespace itk
{
template <typename TInputImage, typename TOutput, typename TCoordinate = float>
class ITK_TEMPLATE_EXPORT ImageFunction : public FunctionBase<Point<TCoordinate, TInputImage::ImageDimension>, TOutput>
{
public:
  ITK_DISALLOW_COPY_AND_MOVE(ImageFunction);

  static constexpr unsigned int ImageDimension = TInputImage::ImageDimension;

  using Self = ImageFunction;
 
  using Superclass = FunctionBase<Point<TCoordinate, Self::ImageDimension>, TOutput>;
 
  using Pointer = SmartPointer<Self>;
  using ConstPointer = SmartPointer<const Self>;

  itkOverrideGetNameOfClassMacro(ImageFunction);

  using InputImageType = TInputImage;

  using InputPixelType = typename InputImageType::PixelType;

  using InputImageConstPointer = typename InputImageType::ConstPointer;

  using OutputType = TOutput;

  using CoordinateType = TCoordinate;
#ifndef ITK_FUTURE_LEGACY_REMOVE
  using CoordRepType ITK_FUTURE_DEPRECATED(
    "ITK 6 discourages using `CoordRepType`. Please use `CoordinateType` instead!") = CoordinateType;
#endif

  using IndexType = typename InputImageType::IndexType;
  using IndexValueType = typename InputImageType::IndexValueType;

  using ContinuousIndexType = ContinuousIndex<TCoordinate, Self::ImageDimension>;

  using PointType = Point<TCoordinate, Self::ImageDimension>;

  virtual void
  SetInputImage(const InputImageType * ptr);

  const InputImageType *
  GetInputImage() const
  {
    return m_Image.GetPointer();
  }

  OutputType
  Evaluate(const PointType & point) const override = 0;

  virtual TOutput
  EvaluateAtIndex(const IndexType & index) const = 0;

  virtual TOutput
  EvaluateAtContinuousIndex(const ContinuousIndexType & index) const = 0;

  virtual bool
  IsInsideBuffer(const IndexType & index) const
  {
    for (unsigned int j = 0; j < ImageDimension; ++j)
    {
      if (index[j] < m_StartIndex[j])
      {
        return false;
      }
      if (index[j] > m_EndIndex[j])
      {
        return false;
      }
    }
    return true;
  }

  virtual bool
  IsInsideBuffer(const ContinuousIndexType & index) const
  {
    for (unsigned int j = 0; j < ImageDimension; ++j)
    {
      /* Test for negative of a positive so we can catch NaN's. */
      if (!(index[j] >= m_StartContinuousIndex[j] && index[j] < m_EndContinuousIndex[j]))
      {
        return false;
      }
    }
    return true;
  }

  virtual bool
  IsInsideBuffer(const PointType & point) const
  {
    const ContinuousIndexType index = m_Image->template TransformPhysicalPointToContinuousIndex<TCoordinate>(point);
    /* Call IsInsideBuffer to test against BufferedRegion bounds.
     * TransformPhysicalPointToContinuousIndex tests against
     * LargestPossibleRegion */
    const bool isInside = IsInsideBuffer(index);
    return isInside;
  }

  void
  ConvertPointToNearestIndex(const PointType & point, IndexType & index) const
  {
    const ContinuousIndexType cindex = m_Image->template TransformPhysicalPointToContinuousIndex<TCoordinate>(point);
    this->ConvertContinuousIndexToNearestIndex(cindex, index);
  }

  void
  ConvertPointToContinuousIndex(const PointType & point, ContinuousIndexType & cindex) const
  {
    cindex = m_Image->template TransformPhysicalPointToContinuousIndex<TCoordinate>(point);
  }

  inline void
  ConvertContinuousIndexToNearestIndex(const ContinuousIndexType & cindex, IndexType & index) const
  {
    index.CopyWithRound(cindex);
  }
 
  itkGetConstReferenceMacro(StartIndex, IndexType);
  itkGetConstReferenceMacro(EndIndex, IndexType);
 
  itkGetConstReferenceMacro(StartContinuousIndex, ContinuousIndexType);
  itkGetConstReferenceMacro(EndContinuousIndex, ContinuousIndexType);
 
protected:
  ImageFunction();
  ~ImageFunction() override = default;
  void
  PrintSelf(std::ostream & os, Indent indent) const override;

  InputImageConstPointer m_Image{};

  IndexType m_StartIndex{};
  IndexType m_EndIndex{};
 
  ContinuousIndexType m_StartContinuousIndex{};
  ContinuousIndexType m_EndContinuousIndex{};
};
} // end namespace itk
 
#ifndef ITK_MANUAL_INSTANTIATION
#  include "itkImageFunction.hxx"
#endif
 
#endif