qgslinearminmaxenhancement.cpp

一个非常好的GIS开源新版本

/* **************************************************************************
              qgslinearminmaxenhancement.cpp -  description
                       -------------------
begin                : Fri Nov 16 2007
copyright            : (C) 2007 by Peter J. Ersts
email                : [e-mail]

****************************************************************************/

/* **************************************************************************
 *                                                                         *
 *   This program is free software; you can redistribute it and/or modify  *
 *   it under the terms of the GNU General Public License as published by  *
 *   the Free Software Foundation; either version 2 of the License, or     *
 *   (at your option) any later version.                                   *
 *                                                                         *
 ***************************************************************************/
 
#include "qgslinearminmaxenhancement.h"

QgsLinearMinMaxEnhancement::QgsLinearMinMaxEnhancement(QgsContrastEnhancement::QgsRasterDataType theQgsRasterDataType, double theMinimumValue, double theMaximumValue) : QgsContrastEnhancementFunction(theQgsRasterDataType, theMinimumValue, theMaximumValue)
{
}

int QgsLinearMinMaxEnhancement::enhanceValue(double theValue)
{
  int myStretchedValue = static_cast<int>(((theValue - mMinimumValue)/(mMinimumMaximumRange))*255.0);
  if(myStretchedValue < 0)
  {
    return 0;
  }
  else if(myStretchedValue > 255)
  {
    return 255;
  }
  
  return myStretchedValue; 
}