/*=========================================================================
 *
 *  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 __itkCustomTransformInitializer_h
#define __itkCustomTransformInitializer_h

#include "itkObject.h"
#include "itkObjectFactory.h"
#include "itkImageMomentsCalculator.h"
#include "itkPointSetMomentsCalculator.h"

#include <iostream>

namespace itk
{
/** \class CustomTransformInitializer
 * \brief CustomTransformInitializer is a helper class intended to
 * initialize the center of rotation and the translation of Transforms having
 * the center of rotation among their parameters.
 *
 * This class is connected to the fixed point set, moving image and transform
 * involved in a point set to image registration.
 *
 * In the second mode, the moments of gray level values are computed
 * for the image while the point set center of mass is computed from the mean
 * of the points. The center of mass of the moving image is then
 * used as center of rotation. The vector between the two centers of
 * mass is passes as the initial translation to the transform. This
 * approach assumes that the moments of the anatomical objects
 * are similar for both images and hence the best initial guess for
 * registration is to superimpose both mass centers.  Note that this
 * assumption will probably not hold in multi-modality registration.
 *
 * \ingroup ITKRegistrationCommon
 * \ingroup ITKTransform
 */
template< class TTransform,
          class TPointSet,
          class TMovingImage >
class ITK_EXPORT CustomTransformInitializer:public Object
{
public:
  /** Standard class typedefs. */
  typedef CustomTransformInitializer Self;
  typedef Object                       Superclass;
  typedef SmartPointer< Self >         Pointer;
  typedef SmartPointer< const Self >   ConstPointer;

  /** New macro for creation of through a Smart Pointer. */
  itkNewMacro(Self);

  /** Run-time type information (and related methods). */
  itkTypeMacro(CustomTransformInitializer, Object);

  /** Type of the transform to initialize */
  typedef TTransform                      TransformType;
  typedef typename TransformType::Pointer TransformPointer;

  /** Dimension of parameters. */
  itkStaticConstMacro(InputSpaceDimension, unsigned int,
                      TransformType::InputSpaceDimension);
  itkStaticConstMacro(OutputSpaceDimension, unsigned int,
                      TransformType::OutputSpaceDimension);

  /** Image Types to use in the initialization of the transform */
  typedef   TPointSet  PointSetType;
  typedef   TMovingImage MovingImageType;

  typedef   typename PointSetType::ConstPointer  PointSetPointer;
  typedef   typename MovingImageType::ConstPointer MovingImagePointer;

  /** Moment calculators */
  typedef PointSetMomentsCalculator< PointSetType >  PointSetCalculatorType;
  typedef ImageMomentsCalculator< MovingImageType > MovingImageCalculatorType;

  typedef typename PointSetCalculatorType::Pointer
  PointSetCalculatorPointer;
  typedef typename MovingImageCalculatorType::Pointer
  MovingImageCalculatorPointer;

  /** Offset type. */
  typedef typename TransformType::OffsetType OffsetType;

  /** Point type. */
  typedef typename TransformType::InputPointType InputPointType;

  /** Vector type. */
  typedef typename TransformType::OutputVectorType OutputVectorType;

  /** Set the transform to be initialized */
  itkSetObjectMacro(Transform,   TransformType);

  /** Set the fixed image used in the registration process */
  itkSetConstObjectMacro(PointSet,  PointSetType);

  /** Set the moving image used in the registration process */
  itkSetConstObjectMacro(MovingImage, MovingImageType);

  /** Initialize the transform using data from the images */
  virtual void InitializeTransform();

  /** Get() access to the moments calculators */
  itkGetConstObjectMacro(FixedCalculator,  PointSetCalculatorType);
  itkGetConstObjectMacro(MovingCalculator, MovingImageCalculatorType);

protected:
  CustomTransformInitializer();
  ~CustomTransformInitializer(){}

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

  itkGetObjectMacro(Transform, TransformType);
private:
  CustomTransformInitializer(const Self &); //purposely not implemented
  void operator=(const Self &);               //purposely not implemented

  TransformPointer m_Transform;

  PointSetPointer m_PointSet;

  MovingImagePointer m_MovingImage;
  PointSetCalculatorPointer  m_FixedCalculator;
  MovingImageCalculatorPointer m_MovingCalculator;
}; //class CustomTransformInitializer
}  // namespace itk

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

#endif /* __itkCustomTransformInitializer_h */