/*=========================================================================

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkUnaryRetractImageFilter.h,v $
  Language:  C++
  Date:      $Date: 2007/02/05 11:15:00 $
  Version:   $Revision: 1.0 $

  Copyright (c) Insight Software Consortium. All rights reserved.
  See ITKCopyright.txt or http://www.itk.org/HTML/Copyright.htm for details.

     This software is distributed WITHOUT ANY WARRANTY; without even 
     the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR 
     PURPOSE.  See the above copyright notices for more information.

=========================================================================*/
#ifndef __itkUnaryRetractImageFilter_h
#define __itkUnaryRetractImageFilter_h

#include "itkImageToImageFilter.h"

namespace itk
{

/** \class UnaryRetractImageFilter
 * \brief Implements generic retraction of a nD time series producing a n-1D output.
 *
 * Contributed by Stefan Roettger, Siemens Medical MR, Mar. 2007
 *
 * This class interpretes the input image as a time series and
 * generates an output image of the next lower dimension.
 * The retraction operation is specified by a functor style template parameter.
 * It receives the time curves of each pixel and produces a single scalar value
 * effectively removing the time dimension of the input image.
 * For example, a 4D times series (generated by the itkNaryElevateImageFilter)
 * will be transformed into a 3D output image by applying the functor to each pixel.
 *
 * A typical times series produced in clinical practice is a MR breast angiography.
 * Gadolinium contrast agent is infused and T1-weighted 3D MR-images are taken every minute.
 * The procedure usually generates 5-10 time points which show the perfusion of the breast tissue.
 * The itkNaryElevateImageFilter can be used to a single 4D image from the original 3D breast images.
 * After this, the itkUnaryRetractFilter can be used to calculate certain characteristics of
 * the time curves which give insight into the malignancy of the breast tissue.
 * Characteristic functor operations are MIPt (Maximum Intensity [Projection] over time) and
 * WI (Wash-In or temporal derivative), for example.
 * A tumor usually shows higher WI values than normal tissue, so that this parameter
 * (amongst a variety of others) can be used to diagnose breast cancer.
 * 
 * \ingroup IntensityImageFilters Multithreaded
 */

template <class TInputImage, class TOutputImage, class TFunction>
class ITK_EXPORT UnaryRetractImageFilter:
  public ImageToImageFilter<TInputImage, TOutputImage>
{
public:

  /** Standard class typedefs. */
  typedef UnaryRetractImageFilter Self;
  typedef ImageToImageFilter<TInputImage, TOutputImage> Superclass;
  typedef SmartPointer<Self> Pointer;
  typedef SmartPointer<const Self> ConstPointer;

  /** Method for creation through the object factory. */
  itkNewMacro(Self);

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

  /** Some typedefs. */
  typedef TFunction FunctorType;
  typedef TInputImage InputImageType;
  typedef typename InputImageType::Pointer     InputImagePointer;
  typedef typename InputImageType::RegionType  InputImageRegionType;
  typedef typename InputImageType::PixelType   InputImagePixelType;
  typedef typename InputImageType::SizeType    InputImageSizeType;
  typedef typename InputImageType::IndexType   InputImageIndexType;
  typedef typename InputImageType::PointType   InputImageOriginType;
  typedef typename InputImageType::SpacingType InputImageSpacingType;
  typedef TOutputImage OutputImageType;
  typedef typename OutputImageType::Pointer     OutputImagePointer;
  typedef typename OutputImageType::RegionType  OutputImageRegionType;
  typedef typename OutputImageType::PixelType   OutputImagePixelType;
  typedef typename OutputImageType::SizeType    OutputImageSizeType;
  typedef typename OutputImageType::IndexType   OutputImageIndexType;
  typedef typename OutputImageType::PointType   OutputImageOriginType;
  typedef typename OutputImageType::SpacingType OutputImageSpacingType;
  typedef Array<InputImagePixelType> NaryArrayType;

  /** ImageDimension constants. */
  itkStaticConstMacro(InputImageDimension, unsigned int, TInputImage::ImageDimension);
  itkStaticConstMacro(OutputImageDimension, unsigned int, TOutputImage::ImageDimension);

  // get the actual functor
  FunctorType& GetFunctor() {return m_Functor;}

  // set the actual functor
  void SetFunctor(FunctorType& functor)
  {
    m_Functor = functor;
    this->Modified();
  }

protected:

  UnaryRetractImageFilter();
  virtual ~UnaryRetractImageFilter() {};

  void GenerateOutputInformation();
  void GenerateData();

private:

  UnaryRetractImageFilter(const Self&); // intentionally not implemented
  void operator=(const Self&);          // intentionally not implemented

  FunctorType m_Functor;
};

}

#ifndef ITK_MANUAL_INSTANTIATION
#include "itkUnaryRetractImageFilter.txx"
#endif

#endif