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filterposterize.cpp

/**********************************************************************************
* Copyright (c) 2003, Matthias Bader and Christoph Rueegg <opendev@cdrnet.ch>     *
* All rights reserved.                                                            *
*                                                                                 *
* Project Website: http://www.cdrnet.net/projects/painter/                        *
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* Redistribution and use in source and binary forms, with or without modification,*
* are permitted provided that the following conditions are met:                   *
*                                                                                 *
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* this list of conditions and the following disclaimer.                           *
*                                                                                 *
* 2. Redistributions in binary form must reproduce the above copyright notice,    *
* this list of conditions and the following disclaimer in the documentation       *
* and/or other materials provided with the distribution.                          *
*                                                                                 *
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"     *
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE       *
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE      *
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE        *
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* THE POSSIBILITY OF SUCH DAMAGE.                                                 *
**********************************************************************************/

#include "filterposterize.h"


PosterizeFilter::PosterizeFilter() : StatelessTransformationFilter() 
{
}

PosterizeFilter::~PosterizeFilter()
{
}

void PosterizeFilter::OnTransform(Channel<unsigned char>* source, Channel<unsigned char>* target, int x0, int y0, int x1, int y1)
{
  int width = target->GetWidth();
  int height = target->GetHeight();
  const int sh = 2;
  int diff;
  
  int current;
  for(int x=0;x<width;x++)
  {
    for(int y=0;y<height;y++)
    {
      diff=0;                           
      current = source->Get(x,y);
      for(int xx=x-sh;xx<=x+sh;xx++)
        if (xx>=0 && xx<width)
          for(int yy=y-sh;yy<=y+sh;yy++)
            if(yy>=0 && yy<height)
              diff += source->Get(xx,yy)-current;

      diff /= 25;

      target->Set(x,y,current+(unsigned char)diff);
    }
  }

  for(int x1=0;x1<ChannelFilter<unsigned char>::GetWidth();x1++)
    for(int y1=0;y1<ChannelFilter<unsigned char>::GetHeight();y1++)
      target->Set(x1,y1,abs((target->Get(x1,y1)/32)<<5));

  
}





ChannelFilter<unsigned char>* PosterizeFilter::EmptyClone()
{
  PosterizeFilter *copy = new PosterizeFilter();
  copy->SetSubChannel(StatelessTransformationFilter::GetSubChannel());
  return(copy);
}

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