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@@ -214,68 +214,11 @@ public: |
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* Return distance using the CIEDE2000 metric, |
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* input should be in CIE L*a*b*. |
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*/ |
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static float DistanceCIEDE2000(vec3 lab1, vec3 lab2) |
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{ |
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float const deg2rad = 6.28318530718f / 360.f; |
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float const rad2deg = 360.f / 6.28318530718f; |
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float C1 = length(lab1.yz); |
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float C2 = length(lab2.yz); |
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float C_ = 0.5f * (C1 + C2); |
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float L1 = lab1.x; |
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float L2 = lab2.x; |
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float dLp = L2 - L1; |
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float L_ = 0.5f * (L1 + L2); |
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float tmp1 = pow(C_, 7.f); |
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float tmp2 = 1.5f - 0.5f * sqrt(tmp1 / (tmp1 + pow(25.f, 7.f))); |
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float ap1 = lab1.y * tmp2; |
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float ap2 = lab2.y * tmp2; |
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float Cp1 = sqrt(ap1 * ap1 + lab1.z * lab1.z); |
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float Cp2 = sqrt(ap2 * ap2 + lab2.z * lab2.z); |
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float dCp = Cp2 - Cp1; |
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float Cp_ = 0.5f * (Cp1 + Cp2); |
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float hp1 = fmod(atan2(lab1.z, ap1) * rad2deg, 360.f); |
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if (hp1 < 0.f) |
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hp1 += 360.f; |
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float hp2 = fmod(atan2(lab2.z, ap2) * rad2deg, 360.f); |
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if (hp2 < 0.f) |
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hp2 += 360.f; |
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float dhp; |
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if (abs(hp1 - hp2) <= 180.f) |
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dhp = hp2 - hp1; |
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else if (hp2 <= hp1) |
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dhp = hp2 - hp1 + 360.f; |
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else |
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dhp = hp2 - hp1 - 360.f; |
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float dHp = 2.f * sqrt(Cp1 * Cp2) * sin(dhp / 2.f * deg2rad); |
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float Hp_; |
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if (abs(hp1 - hp2) > 180.f) |
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Hp_ = 0.5f * (hp1 + hp2 + 360.f); |
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else |
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Hp_ = 0.5f * (hp1 + hp2); |
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float T = 1.f - 0.17f * cos((Hp_ - 30.f) * deg2rad) |
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+ 0.24f * cos(2 * Hp_ * deg2rad) |
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+ 0.32f * cos((3.f * Hp_ + 6.f) * deg2rad) |
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- 0.20f * cos((4.f * Hp_ - 63.f) * deg2rad); |
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float SL = 1.f + 0.015f * (L_ - 50) * (L_ - 50) |
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/ sqrt(20.f + (L_ - 50) * (L_ - 50)); |
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float SC = 1.f + 0.045f * Cp_; |
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float SH = 1.f + 0.015f * Cp_ * T; |
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float RT = -2.f * sqrt(pow(Cp_, 7.f) / (pow(Cp_, 7.f) + pow(25.f, 7.f))) |
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* sin(60.f * deg2rad * exp(-pow((Hp_ - 275.f) / 25.f, 2.f))); |
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dLp /= SL; |
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dCp /= SC; |
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dHp /= SH; |
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return sqrt(dLp * dLp + dCp * dCp + dHp * dHp + RT * dCp * dHp); |
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} |
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static float DistanceCIEDE2000(vec3 lab1, vec3 lab2); |
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/* Convert a wavelength to an xyY fully saturated colour */ |
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/* |
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* Convert a wavelength into an xyY fully saturated colour. |
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*/ |
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static vec3 WavelengthToCIExyY(float nm); |
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}; |
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