rtkHomogeneousMatrix.h

Go to the documentation of this file.

/*=========================================================================
 *
 *  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.
 *
 *=========================================================================*/

#ifndef rtkHomogeneousMatrix_h
#define rtkHomogeneousMatrix_h

#include <itkMatrix.h>
#include <itkImage.h>

namespace rtk
{

//--------------------------------------------------------------------
// template <class TPixel, unsigned int VImageDimension>
template <class TImageType>
itk::Matrix<double, TImageType::ImageDimension + 1, TImageType::ImageDimension + 1>
GetIndexToPhysicalPointMatrix(const TImageType * image)
{
  const unsigned int Dimension = TImageType::ImageDimension;

  itk::Matrix<double, Dimension + 1, Dimension + 1> matrix;
  matrix.Fill(0.0);

  itk::Index<Dimension>         index;
  itk::Point<double, Dimension> point;

  for (unsigned int j = 0; j < Dimension; j++)
  {
    index.Fill(0);
    index[j] = 1;
    image->TransformIndexToPhysicalPoint(index, point);
    for (unsigned int i = 0; i < Dimension; i++)
      matrix[i][j] = point[i] - image->GetOrigin()[i];
  }
  for (unsigned int i = 0; i < Dimension; i++)
    matrix[i][Dimension] = image->GetOrigin()[i];
  matrix[Dimension][Dimension] = 1.0;

  return matrix;
};

//--------------------------------------------------------------------
// template <class TPixel, unsigned int VImageDimension>
template <class TImageType>
itk::Matrix<double, TImageType::ImageDimension + 1, TImageType::ImageDimension + 1>
GetPhysicalPointToIndexMatrix(const TImageType * image)
{
  using MatrixType = itk::Matrix<double, TImageType::ImageDimension + 1, TImageType::ImageDimension + 1>;
  return MatrixType(GetIndexToPhysicalPointMatrix<TImageType>(image).GetInverse());
};

} // namespace rtk

#endif // rtkHomogeneousMatrix_h