imageUtil.h

   1 #ifndef IMAGEUTIL_HEADER_
   2 #define IMAGEUTIL_HEADER_
   3
   4 #include "headers.h"
   5
   6 #include <QColor>
   7
   8 namespace Color {
   9         extern const Real RGBCoeffs[][4]        ///  RGB color coefficients
  10                 , YCbCrCoeffs[][4];                             ///< YCbCr color coefficients
  11
  12         /** Computes PSNRs between two images for gray, red, green and blue */
  13         std::vector<Real> getPSNR(const QImage &a,const QImage &b);
  14
  15         /** Computes the amount of a color (coefficients as a parameter) in RGB */
  16         inline Real getColor( QRgb color, const Real *koefs ) {
  17             return koefs[3] + std::ldexp( Real(0.5) + qRed(color)*Real(koefs[0])
  18                 + qGreen(color)*Real(koefs[1]) + qBlue(color)*Real(koefs[2]), -8 );
  19         }
  20
  21         /** Converts color from a model (coefficients as a parameter) to RGB */
  22         inline QRgb getColor( const Real (*coeffs)[4], const Real *planes ) {
  23                 Real rgb[3]= {0,0,0};
  24                 for (int i=0; i<3; ++i) {
  25                         const Real *cLine= coeffs[i];
  26                         Real col= planes[i]+cLine[3];
  27                         for (int c=0; c<3; ++c)
  28                                 rgb[c]+= col*cLine[c];
  29                 }
  30                 typedef Float2int<8,Real> Conv;
  31                 return qRgb( Conv::convertCheck(rgb[0]), Conv::convertCheck(rgb[1])
  32                         , Conv::convertCheck(rgb[2]) );
  33         }
  34
  35         /** Computes the gray level of a QRgb color in 0-255 interval */
  36         inline int getGray(QRgb color) {
  37                 return Float2int<8,Real>::convert( getColor( color, YCbCrCoeffs[0] ) );
  38         }
  39
  40 } // Color namespace
  41
  42 #endif