diff options
Diffstat (limited to 'src/ipa/libipa/colours.cpp')
| -rw-r--r-- | src/ipa/libipa/colours.cpp | 22 |
1 files changed, 9 insertions, 13 deletions
diff --git a/src/ipa/libipa/colours.cpp b/src/ipa/libipa/colours.cpp index 9fcb53b0..6c597093 100644 --- a/src/ipa/libipa/colours.cpp +++ b/src/ipa/libipa/colours.cpp @@ -21,9 +21,7 @@ namespace ipa { /** * \brief Estimate luminance from RGB values following ITU-R BT.601 - * \param[in] r The red value - * \param[in] g The green value - * \param[in] b The blue value + * \param[in] rgb The RGB value * * This function estimates a luminance value from a triplet of Red, Green and * Blue values, following the formula defined by ITU-R Recommendation BT.601-7 @@ -31,21 +29,19 @@ namespace ipa { * * \return The estimated luminance value */ -double rec601LuminanceFromRGB(double r, double g, double b) +double rec601LuminanceFromRGB(const RGB<double> &rgb) { - return (r * .299) + (g * .587) + (b * .114); + return (rgb.r() * .299) + (rgb.g() * .587) + (rgb.b() * .114); } /** * \brief Estimate correlated colour temperature from RGB color space input - * \param[in] red The input red value - * \param[in] green The input green value - * \param[in] blue The input blue value + * \param[in] rgb The RGB value * * This function estimates the correlated color temperature RGB color space * input. In physics and color science, the Planckian locus or black body locus * is the path or locus that the color of an incandescent black body would take - * in a particular chromaticity space as the blackbody temperature changes. + * in a particular chromaticity space as the black body temperature changes. * * If a narrow range of color temperatures is considered (those encapsulating * daylight being the most practical case) one can approximate the Planckian @@ -56,12 +52,12 @@ double rec601LuminanceFromRGB(double r, double g, double b) * * \return The estimated color temperature */ -uint32_t estimateCCT(double red, double green, double blue) +uint32_t estimateCCT(const RGB<double> &rgb) { /* Convert the RGB values to CIE tristimulus values (XYZ) */ - double X = (-0.14282) * (red) + (1.54924) * (green) + (-0.95641) * (blue); - double Y = (-0.32466) * (red) + (1.57837) * (green) + (-0.73191) * (blue); - double Z = (-0.68202) * (red) + (0.77073) * (green) + (0.56332) * (blue); + double X = (-0.14282) * rgb.r() + (1.54924) * rgb.g() + (-0.95641) * rgb.b(); + double Y = (-0.32466) * rgb.r() + (1.57837) * rgb.g() + (-0.73191) * rgb.b(); + double Z = (-0.68202) * rgb.r() + (0.77073) * rgb.g() + (0.56332) * rgb.b(); /* Calculate the normalized chromaticity values */ double x = X / (X + Y + Z); |