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

  Program:   Insight Segmentation & Registration Toolkit
  Module:    $RCSfile: itkComposeRGBImageFilter.h,v $
  Language:  C++
  Date:      $Date: 2006/01/23 17:55:47 $
  Version:   $Revision: 1.7 $

  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 __itkComposeRGBImageFilter_h
#define __itkComposeRGBImageFilter_h

#include "itkTernaryFunctorImageFilter.h"
#include "itkRGBPixel.h"

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

namespace itk
{
  
namespace Function {  
  
template< class TInput >
class ComposeRGB
{
public:
  typedef RGBPixel<TInput> OutputType;
  ComposeRGB() {}
  ~ComposeRGB() {}
  bool operator!=( const ComposeRGB & ) const
  {
    return false;
  }
  bool operator==( const ComposeRGB & other ) const
  {
    return !(*this != other);
  }
  inline OutputType operator()(  const TInput & R, 
                                 const TInput & G,
                                 const TInput & B)
  {
    OutputType rgbPixel;
    rgbPixel.Set( R, G, B);
    return rgbPixel;
  }
}; 
}

template <typename TInputImage, 
          typename TOutputImage= 
          Image< RGBPixel< ITK_TYPENAME TInputImage::PixelType >,
                 ::itk::GetImageDimension<TInputImage>::ImageDimension > >
class ITK_EXPORT ComposeRGBImageFilter :
    public
TernaryFunctorImageFilter<TInputImage,TInputImage,
                          TInputImage,TOutputImage, 
                          Function::ComposeRGB< ITK_TYPENAME TInputImage::PixelType >   >
{
public:
  /** Standard class typedefs. */
  typedef ComposeRGBImageFilter  Self;
  typedef TernaryFunctorImageFilter<TInputImage,TInputImage,
                                    TInputImage,TOutputImage, 
                                    Function::ComposeRGB< 
    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:
  ComposeRGBImageFilter() {}
  virtual ~ComposeRGBImageFilter() {}

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


};

} // end namespace itk


#endif
