sharpen.h File Reference

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Functions
void	sharpenImage (QImage &image, float sigma, QPoint offset, QSize fullImageRes, QImage *edgeImage, bool blurEdges)

Function Documentation

sharpenImage()

void sharpenImage	(	QImage &	image,
		float	sigma,
		QPoint	offset,
		QSize	fullImageRes,
		QImage *	edgeImage,
		bool	blurEdges )

Definition at line 95 of file sharpen.cpp.

{
  //construct blur copy
  QImage blurredImage = image.copy();
  blurImage( blurredImage, sigma );
  
  //iterate over each pixel and adjust luminance value
  int x, y;
  QRgb *origRgb, *blurredRgb, *edgeRgb;
  uchar *origScanline;
  uchar *blurredScanline;
  uchar *edgesScanline = NULL;
  
  for(y=0; y<image.height(); y++)
  {
    origScanline = image.scanLine(y);
    blurredScanline = blurredImage.scanLine(y);
    if( edgeImage != NULL )
    {
      int edgeY = ((edgeImage->height()-1) * (y+offset.y())) / (fullImageRes.height()-1);
      edgesScanline = edgeImage->scanLine(edgeY);
    }
    
    for(x=0; x<image.width(); x++)
    {
      //get rgb triplets
      origRgb = ((QRgb*)origScanline+x);
      double r1 = ((double)qRed(*origRgb)   )/255.0;
      double g1 = ((double)qGreen(*origRgb) )/255.0;
      double b1 = ((double)qBlue(*origRgb)  )/255.0;
      
      blurredRgb = ((QRgb*)blurredScanline+x);
      double r2 = ((double)qRed(*blurredRgb)   )/255.0;
      double g2 = ((double)qGreen(*blurredRgb) )/255.0;
      double b2 = ((double)qBlue(*blurredRgb)  )/255.0;
 
      //sharpen the entire thing!
      float alpha;
      if( edgeImage == NULL)
        alpha = 1.0f;
      else
      {
        int edgeX = ((edgeImage->width()-1) * (x+offset.x())) / (fullImageRes.width()-1);
        edgeRgb = ((QRgb*)edgesScanline+edgeX);
        
        alpha = ((float) qRed( *edgeRgb )) / 255.0f;
        
        //blur regions, not edges
        if(!blurEdges)
          alpha = 1.0f - alpha;
      }
      
      //convert to hsv
      double h1,s1,v1;
      RGBtoHSV(r1,g1,b1,&h1,&s1,&v1);
 
      double h2,s2,v2;
      RGBtoHSV(r2,g2,b2,&h2,&s2,&v2);
      
      //reset v
      v1  = (alpha * MIN( MAX(2*v1 - v2, 0), 1.0 )) + (1-alpha)*v1;
      
      //convert adjusted color back to rgb colorspace and clamp
      HSVtoRGB( &r1,&g1,&b1, h1,s1,v1);         
      int rp = (int) MIN( MAX((r1*255), 0), 255 );
      int gp = (int) MIN( MAX((g1*255), 0), 255 );
      int bp = (int) MIN( MAX((b1*255), 0), 255 );
      
      //set adjusted color value
      *origRgb = qRgb(rp,gp,bp);
    } //x
  } //y
 
}

References b1, b2, blurImage(), edgeImage, HSVtoRGB(), MAX, MIN, and RGBtoHSV().

Referenced by GrainEditor::adjustImage().