itkImageFunction.h

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/*=========================================================================
 *
 *  Copyright Insight Software 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
 *
 *         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.
 *
 *=========================================================================*/
#ifndef itkImageFunction_h
#define itkImageFunction_h

#include "itkFunctionBase.h"
#include "itkIndex.h"
#include "itkImageBase.h"

namespace itk
{
template<
  typename TInputImage,
  typename TOutput,
  typename TCoordRep = float
  >
class ITK_TEMPLATE_EXPORT ImageFunction:
    public FunctionBase< Point< TCoordRep, TInputImage::ImageDimension >, TOutput >
{
public:
  ITK_DISALLOW_COPY_AND_ASSIGN(ImageFunction);

  static constexpr unsigned int ImageDimension = TInputImage::ImageDimension;

  using Self = ImageFunction;

  using Superclass = FunctionBase<
    Point< TCoordRep,
           Self::ImageDimension >,
           TOutput >;

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

  itkTypeMacro(ImageFunction, FunctionBase);

  using InputImageType = TInputImage;

  using InputPixelType = typename InputImageType::PixelType;

  using InputImageConstPointer = typename InputImageType::ConstPointer;

  using OutputType = TOutput;

  using CoordRepType = TCoordRep;

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

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

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

  virtual void SetInputImage(const InputImageType *ptr);

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

  TOutput 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
  {
    ContinuousIndexType index;
    m_Image->TransformPhysicalPointToContinuousIndex(point, index);
    /* Call IsInsideBuffer to test against BufferedRegion bounds.
     * TransformPhysicalPointToContinuousIndex tests against
     * LargestPossibleRegion */
    bool isInside = IsInsideBuffer( index );
    return isInside;
  }

  void ConvertPointToNearestIndex(const PointType & point,
                                  IndexType & index) const
  {
    ContinuousIndexType cindex;

    m_Image->TransformPhysicalPointToContinuousIndex(point, cindex);
    this->ConvertContinuousIndexToNearestIndex(cindex, index);
  }

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

  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