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filterunsharp.cpp

/**********************************************************************************
* Copyright (c) 2003, Christoph Rueegg <opendev@cdrnet.ch> and Matthias Bader     *
* All rights reserved.                                                            *
*                                                                                 *
* Project Website: http://www.cdrnet.net/projects/painter/                        *
*                                                                                 *
* Redistribution and use in source and binary forms, with or without modification,*
* are permitted provided that the following conditions are met:                   *
*                                                                                 *
* 1. Redistributions of source code must retain the above copyright notice,       *
* 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        *
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR             *
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF            *
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS        *
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN         *
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF          *
* THE POSSIBILITY OF SUCH DAMAGE.                                                 *
**********************************************************************************/

#include "filterunsharp.h"
#include <cmath>

UnsharpFilter::UnsharpFilter() : StatelessTransformationFilter() {}

UnsharpFilter::~UnsharpFilter() {}

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

void UnsharpFilter::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();
  int sh = (int)((abs(x1-x0) + abs(y1-y0))*(50.0/(width+height)));
  if(sh < 3)
    sh = 3;
  int diff;    
//  double 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 /= (1+2*sh)*(1+2*sh);
       
      target->Set(x,y,current+(unsigned char)diff);
    }
  }
}

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