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

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkComposeRGBAImageFilter.h,v $
  Language:  C++
  Date:      $Date: 2007/05/10 07:00:00 $
  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 __itkComposeRGBAImageFilter_h
#define __itkComposeRGBAImageFilter_h

#include "itkNaryFunctorImageFilter.h"
#include "itkRGBAPixel.h"
#include "itkNumericTraitsRGBAPixel.h"

/** \class ComposeRGBAImageFilter
 * \brief Implements pixel-wise composition of an RGBA pixel from four scalar images.
 *
 * This filter receives four scalar images as input. Each image containing
 * one of the RGBA components of a color image. The filter produces as output an
 * RGBA image in which the four components have been unified. The Component
 * type is preserved from the PixelType of the input images.
 *
 * \ingroup IntensityImageFilters
 */

namespace itk
{
  
namespace Functor {  
  
template< class TInput >
class ComposeRGBA
{
public:
  typedef RGBAPixel<TInput> OutputType;
  ComposeRGBA() {}
  ~ComposeRGBA() {}
  bool operator!=( const ComposeRGBA & ) const
  {
    return false;
  }
  bool operator==( const ComposeRGBA & other ) const
  {
    return !(*this != other);
  }
  inline OutputType operator()(  const std::vector< TInput > & in )
  {
    OutputType pixel;
    pixel.Set( in[0], in[1], in[2], in[3] );
    return pixel;
  }
}; 
}

template <typename TInputImage, 
          typename TOutputImage= 
          Image< RGBAPixel< ITK_TYPENAME TInputImage::PixelType >,
                 ::itk::GetImageDimension<TInputImage>::ImageDimension > >
class ITK_EXPORT ComposeRGBAImageFilter :
    public
NaryFunctorImageFilter<TInputImage,TOutputImage, 
                       Functor::ComposeRGBA< ITK_TYPENAME TInputImage::PixelType >   >
{
public:
  /** Standard class typedefs. */
  typedef ComposeRGBAImageFilter  Self;
  typedef NaryFunctorImageFilter<TInputImage,TOutputImage,
                                 Functor::ComposeRGBA<ITK_TYPENAME TInputImage::PixelType > >  Superclass;
  typedef SmartPointer<Self>        Pointer;
  typedef SmartPointer<const Self>  ConstPointer;

  typedef typename Superclass::OutputImageType OutputImageType;
  
  /** Method for creation through the object factory. */
  itkNewMacro(Self);

protected:
  ComposeRGBAImageFilter() {}
  virtual ~ComposeRGBAImageFilter() {}

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


};

} // end namespace itk


#endif