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

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkVectorExpandImageFilter.h,v $
  Language:  C++
  Date:      $Date: 2006-04-03 15:07:52 $
  Version:   $Revision: 1.15 $

  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 __itkVectorExpandImageFilter_h
#define __itkVectorExpandImageFilter_h

#include "itkImageToImageFilter.h"
#include "itkVectorInterpolateImageFunction.h"
#include "itkVectorLinearInterpolateImageFunction.h"

namespace itk
{

/** \class VectorExpandImageFilter
 * \brief Expand the size of a vector image by an integer factor in each
 * dimension.
 *
 * VectorExpandImageFilter increases the size of an image by an integer
 * factor in each dimension using a interpolation method.
 * The output image size in each dimension is given by:
 *
 * OutputSize[j] = InputSize[j] * ExpandFactors[j]
 *
 * The output values are obtained by interpolating the input image.
 * The default interpolation type used is the 
 * VectorLinearInterpolateImageFunction.
 * The user can specified a particular interpolation function via
 * SetInterpolator(). Note that the input interpolator must derive
 * from base class VectorInterpolateImageFunction.
 *
 * When the LargestPossibleRegion is requested, the output image will
 * contain padding at the upper edge of each dimension. The width
 * of padding in the i'th dimension is (ExpandFactors[i] - 1). Users can
 * specify the padding value used by setting the EdgePaddingValue.
 *
 * This filter will produce an output with different pixel spacing
 * that its input image such that:
 *
 * OutputSpacing[j] = InputSpacing[j] / ExpandFactors[j]
 *
 * The filter is templated over the input image type and the output 
 * image type.
 *
 * This filter is implemented as a multithreaded filter and supports
 * streaming.
 *
 * \warning This filter only works for image with pixel types
 * base on itk::Vectors. For scalar pixel images use
 * ExpandImageFilter.
 *
 * This filter assumes that the input and output image has the same
 * number of dimensions, and that the input and output pixel types
 * have the same vector dimension.
 *
 * \sa Vector
 * \sa VectorInterpolateImageFunction
 * \sa VectorLinearInterpolationImageFunction
 *
 * \sa ExpandImageFilter
 *
 * \ingroup GeometricTransform
 */
template <
class TInputImage, 
class TOutputImage 
>
class ITK_EXPORT VectorExpandImageFilter:
  public ImageToImageFilter<TInputImage,TOutputImage>
{
public:
  /** Standard class typedefs. */
  typedef VectorExpandImageFilter         Self;
  typedef ImageToImageFilter<TInputImage,TOutputImage>  Superclass;
  typedef SmartPointer<Self>  Pointer;
  typedef SmartPointer<const Self>  ConstPointer;

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

  /** Typedef to describe the output image region type. */
  typedef typename TInputImage::Pointer InputImagePointer;
  typedef typename TOutputImage::Pointer OutputImagePointer;
  typedef typename TOutputImage::RegionType OutputImageRegionType;

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

  /** ImageDimension enumeration */
  itkStaticConstMacro(ImageDimension, unsigned int,
                      TInputImage::ImageDimension);

  /** Inherit some types from superclass */
  typedef typename Superclass::InputImageType  InputImageType;
  typedef typename Superclass::OutputImageType OutputImageType;

  /** Input/output vector types. */
  typedef typename OutputImageType::PixelType  OutputPixelType;
  typedef typename OutputPixelType::ValueType  OutputValueType;
  typedef typename InputImageType::PixelType  InputPixelType;
  typedef typename InputPixelType::ValueType   InputValueType;

  /** Determine the vector dimension. */
  enum { VectorDimension = InputPixelType::Dimension };

  /** The type of the expand factors representation */
  typedef float  ExpandFactorsType;

  /** Typedef support for the interpolation function */
  typedef double CoordRepType;
  typedef VectorInterpolateImageFunction<InputImageType,CoordRepType> 
    InterpolatorType;
  typedef typename InterpolatorType::Pointer InterpolatorPointer;
  typedef VectorLinearInterpolateImageFunction<InputImageType,CoordRepType> 
    DefaultInterpolatorType;

  /** Set the interpolator function. */
  itkSetObjectMacro( Interpolator, InterpolatorType );

  /** Get a pointer to the interpolator function. */
  itkGetObjectMacro( Interpolator, InterpolatorType );

  /** Set the expand factors. Values are clamped to 
   * a minimum value of 1. Default is 1 for all dimensions. */
  virtual void SetExpandFactors( const ExpandFactorsType factors[] );
  virtual void SetExpandFactors( const ExpandFactorsType factor );
  virtual void SetExpandFactors( const unsigned int factors[] );

  /** Get the expand factors. */
  const ExpandFactorsType * GetExpandFactors() const
    { return m_ExpandFactors; }

  /** Set the edge padding value. The default is a vector of zero. */
  virtual void SetEdgePaddingValue( const OutputPixelType& value );

  /** Get the edge padding value. */
  virtual const OutputPixelType& GetEdgePaddingValue()
    { return m_EdgePaddingValue; }

  /** VectorExpandImageFilter produces an image which is a different
   * resolution and with a different pixel spacing than its input image.  As
   * such, VectorExpandImageFilter needs to provide an implementation for
   * UpdateOutputInformation() in order to inform the pipeline execution
   * model.  The original documentation of this method is below.  \sa
   * ProcessObject::GenerateOutputInformaton() */
  virtual void GenerateOutputInformation();

  /** VectorExpandImageFilter needs a smaller input requested region than the
   * output requested region.  As such, ShrinkImageFilter needs to provide an
   * implementation for GenerateInputRequestedRegion() in order to inform the
   * pipeline execution model.  \sa
   * ProcessObject::GenerateInputRequestedRegion() */
  virtual void GenerateInputRequestedRegion();

#ifdef ITK_USE_CONCEPT_CHECKING
  /** Begin concept checking */
  itkConceptMacro(InputHasNumericTraitsCheck,
                  (Concept::HasNumericTraits<InputValueType>));
  itkConceptMacro(OutputHasNumericTraitsCheck,
                  (Concept::HasNumericTraits<OutputValueType>));
  /** End concept checking */
#endif

protected:

  VectorExpandImageFilter();
  ~VectorExpandImageFilter() {};
  void PrintSelf(std::ostream& os, Indent indent) const;

  /** VectorExpandImageFilter is implemented as a multithreaded filter.
   * Therefore, this implementation provides a ThreadedGenerateData() routine
   * which is called for each processing thread. The output image data is
   * allocated automatically by the superclass prior to calling
   * ThreadedGenerateData().  ThreadedGenerateData can only write to the
   * portion of the output image specified by the parameter
   * "outputRegionForThread" \sa ImageToImageFilter::ThreadedGenerateData(),
   * ImageToImageFilter::GenerateData() */
  virtual
  void ThreadedGenerateData(const OutputImageRegionType& outputRegionForThread,
                            int threadId );
  
  /** This method is used to set the state of the filter before 
   * multi-threading. */
  virtual void BeforeThreadedGenerateData();

private:
  VectorExpandImageFilter(const Self&); //purposely not implemented
  void operator=(const Self&); //purposely not implemented

  ExpandFactorsType      m_ExpandFactors[ImageDimension];
  InterpolatorPointer    m_Interpolator;
  OutputPixelType        m_EdgePaddingValue;
 
};

} // end namespace itk

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

#endif