cmtkTransformChangeToSpaceAffine.cxx

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/*
//
//  Copyright 1997-2009 Torsten Rohlfing
//
//  Copyright 2004-2010 SRI International
//
//  This file is part of the Computational Morphometry Toolkit.
//
//  http://www.nitrc.org/projects/cmtk/
//
//  The Computational Morphometry Toolkit is free software: you can
//  redistribute it and/or modify it under the terms of the GNU General Public
//  License as published by the Free Software Foundation, either version 3 of
//  the License, or (at your option) any later version.
//
//  The Computational Morphometry Toolkit is distributed in the hope that it
//  will be useful, but WITHOUT ANY WARRANTY; without even the implied
//  warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//  GNU General Public License for more details.
//
//  You should have received a copy of the GNU General Public License along
//  with the Computational Morphometry Toolkit.  If not, see
//  <http://www.gnu.org/licenses/>.
//
//  $Revision: 2479 $
//
//  $LastChangedDate: 2010-10-20 15:35:37 -0700 (Wed, 20 Oct 2010) $
//
//  $LastChangedBy: torstenrohlfing $
//
*/

#include "cmtkTransformChangeToSpaceAffine.h"

cmtk::TransformChangeToSpaceAffine
::TransformChangeToSpaceAffine
( const AffineXform& xform, const UniformVolume& reference, const UniformVolume& floating, const char* forceSpace )
{
// adapt transformation to Slicer's image coordinate systems as defined in the Nrrd files we probably read
  UniformVolume::SmartPtr refVolumeOriginalSpace( reference.CloneGrid() );
  UniformVolume::SmartPtr fltVolumeOriginalSpace( floating.CloneGrid() );
  
  // first bring volumes back into their native coordinate space, or into forced space if one is provided.
  if ( forceSpace )
    {
    refVolumeOriginalSpace->ChangeCoordinateSpace( forceSpace );
    fltVolumeOriginalSpace->ChangeCoordinateSpace( forceSpace );
    }
  else
    {
    refVolumeOriginalSpace->ChangeCoordinateSpace( reference.m_MetaInformation[META_SPACE_ORIGINAL] );
    fltVolumeOriginalSpace->ChangeCoordinateSpace( floating.m_MetaInformation[META_SPACE_ORIGINAL] );
    }
  
  // now determine image-to-physical transformations and concatenate these.
  const AffineXform::MatrixType refMatrix = refVolumeOriginalSpace->GetImageToPhysicalMatrix();
  const AffineXform::MatrixType fltMatrix = fltVolumeOriginalSpace->GetImageToPhysicalMatrix();
  
  const AffineXform::MatrixType concatMatrix = (refMatrix.GetInverse() * xform.Matrix) * fltMatrix;
  
  // create output transformation and write
  this->m_NewXform.SetMatrix( concatMatrix );
}