#ifndef IPTEMPORALAVERAGE_HEADER
#define IPTEMPORALAVERAGE_HEADER 1
//////////////////////////////////////////////////////////
//! rcsid="$Id: TemporalAverage.hh,v 1.3 2000/07/07 12:57:58 ees1cg Exp $"
//! file="amma/Image/IPStream/IPLinear/TemporalAverage.hh"
//! lib=IPLinear
//! docentry="default.Charles Galambos"
//! author="Charles Galambos"
//! date="04/07/2000"

#include "amma/DP/Process.hh"
#include "amma/Ring.hh"
#include "amma/Image.hh"
#include "amma/Image4Iter.hh"
#include <assert.h>

//! userlevel=Develop
//: Temporal Average of images.

template <class TypeT>
class IPTemporalAverageBodyC
  : public DPProcessBodyC<ImageC<TypeT>,ImageC<TypeT> >
{
public:
  IPTemporalAverageBodyC(IntT len = 5)
    : buffLen(len),
      sr(len),
      full(false)
    { assert(len > 1); }
  //: Constructor.
  
  virtual ImageC<TypeT> Apply (const ImageC<TypeT> &im);
  //: Apply to image.
  // NB. The first 'len' applications will not be fully filtered.
  
protected:
  IntT buffLen;
  RingBuffC<ImageC<TypeT> > sr;
  ImageC<TypeT> sum;
  BooleanT full;
};

//! userlevel=Normal
//: Temporal Average of images.

template <class TypeT>
class IPTemporalAverageC
  : public DPProcessC<ImageC<TypeT>,ImageC<TypeT> >
{
public:
  IPTemporalAverageC()
    {}
  //: Default constructor.
  // Creates an invalid handle.

  IPTemporalAverageC(IntT len)
    : DPProcessC<ImageC<TypeT>,ImageC<TypeT> >(*new IPTemporalAverageBodyC<TypeT>(len))
    {}
  //: Constructor.
};

//////////////////////////////////////////////////////////////////////////////////////////

template <class TypeT>
ImageC<TypeT> IPTemporalAverageBodyC<TypeT>::Apply (const ImageC<TypeT> &im) {
  if(full) { // Normal running buffer...
    if(im.Rectangle() != sum.Rectangle()) {
      cerr << "IPTemporalAverageBodyC<TypeT>::Apply (), Size mismatch. \n";
      return im;
    }
    
    ImageC<TypeT> ret(sum.Rectangle());
    ImageC<TypeT> old = sr.GetLast();
    for(Image4IterC<TypeT,TypeT,TypeT,TypeT> it(ret,sum,im,old);it.IsElm();it.Next()) {
      it.Data2() += it.Data3() - it.Data4();
      it.Data1() = it.Data2() / buffLen;
    }
    
    sr.Insert(im);
    return ret;
  }
  
  sr.Insert(im);
  if(sr.Items() == 1) { // Initalise sum ?
    sum = ImageC<TypeT>(im.Rectangle()); // Setup sum.
    for(Image2IterC<TypeT,TypeT> it(sum,im);it.IsElm();it.Next()) 
      it.Data1() = it.Data2();
    return im;
  }
  
  // Fill buffer.
  
  if(im.Rectangle() != sum.Rectangle()) {
    cerr << "IPTemporalAverageBodyC<TypeT>::Apply (), Size mismatch. \n";
    return im;
  }
  
  ImageC<TypeT> ret(im.Rectangle());
  TypeT curBuffSize = (TypeT) sr.Items();
  for(Image3IterC<TypeT,TypeT,TypeT> it(ret,sum,im);it.IsElm();it.Next()) {
    it.Data2() += it.Data3();
    it.Data1() = it.Data2() / curBuffSize; 
  }
  if(sr.Items() == buffLen)
    full = true;
  return ret;
}


#endif