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Fix some bugs in color calculations 

Add gamma correction
This commit is contained in:
Massimiliano Corsini 2006-08-24 16:51:06 +00:00
parent c6fc770fd9
commit a4dec0385d
1 changed files with 242 additions and 99 deletions
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341
vcg/space/colorspace.h
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@ -348,77 +348,6 @@ private:
return XYZ_TO_RGB[index];
}
static Illuminant refIlluminant(RGBSpaces rgb_space)
{
// RGB WORKING SPACE DATA
//
// Illuminant Reference for each RGB Space.
//
if (rgb_space == ADOBE_RGB)
{
return ILLUMINANT_D65;
}
else if (rgb_space == APPLE_RGB)
{
return ILLUMINANT_D65;
}
else if (rgb_space == BEST_RGB)
{
return ILLUMINANT_D50;
}
else if (rgb_space == BETA_RGB)
{
return ILLUMINANT_D50;
}
else if (rgb_space == BRUCE_RGB)
{
return ILLUMINANT_D65;
}
else if (rgb_space == CIE_RGB)
{
return ILLUMINANT_E;
}
else if (rgb_space == DON_RGB4)
{
return ILLUMINANT_D50;
}
else if (rgb_space == ECI_RGB)
{
return ILLUMINANT_D50;
}
else if (rgb_space == EKTA_SPACE)
{
return ILLUMINANT_D50;
}
else if (rgb_space == NTSC_RGB)
{
return ILLUMINANT_C;
}
else if (rgb_space == PAL_RGB)
{
return ILLUMINANT_D65;
}
else if (rgb_space == PROPHOTO)
{
return ILLUMINANT_D50;
}
else if (rgb_space == SMPTE_C)
{
return ILLUMINANT_D65;
}
else if (rgb_space == SRGB)
{
return ILLUMINANT_D65;
}
else if (rgb_space == WIDE_GAMUT)
{
return ILLUMINANT_D50;
}
else
assert(false);
}
static double CA(int index)
{
// CHROMATIC ADAPTATION MATRIX
@ -1379,12 +1308,149 @@ private:
// public methods
public:
static double gamma(RGBSpaces rgb_space)
{
if (rgb_space == ADOBE_RGB)
{
return 2.2;
}
else if (rgb_space == APPLE_RGB)
{
return 1.8;
}
else if (rgb_space == BEST_RGB)
{
return 2.2;
}
else if (rgb_space == BETA_RGB)
{
return 2.2;
}
else if (rgb_space == BRUCE_RGB)
{
return 2.2;
}
else if (rgb_space == CIE_RGB)
{
return 2.2;
}
else if (rgb_space == DON_RGB4)
{
return 1.8;
}
else if (rgb_space == ECI_RGB)
{
return 2.2;
}
else if (rgb_space == EKTA_SPACE)
{
return 2.2;
}
else if (rgb_space == NTSC_RGB)
{
return 2.2;
}
else if (rgb_space == PAL_RGB)
{
return 2.2;
}
else if (rgb_space == PROPHOTO)
{
return 1.8;
}
else if (rgb_space == SMPTE_C)
{
return 2.2;
}
else if (rgb_space == SRGB)
{
return 2.2; // about 2.2
}
else if (rgb_space == WIDE_GAMUT)
{
return 2.2;
}
else
assert(false);
}
static Illuminant refIlluminant(RGBSpaces rgb_space)
{
// RGB WORKING SPACE DATA
//
// Illuminant Reference for each RGB Space.
//
if (rgb_space == ADOBE_RGB)
{
return ILLUMINANT_D65;
}
else if (rgb_space == APPLE_RGB)
{
return ILLUMINANT_D65;
}
else if (rgb_space == BEST_RGB)
{
return ILLUMINANT_D50;
}
else if (rgb_space == BETA_RGB)
{
return ILLUMINANT_D50;
}
else if (rgb_space == BRUCE_RGB)
{
return ILLUMINANT_D65;
}
else if (rgb_space == CIE_RGB)
{
return ILLUMINANT_E;
}
else if (rgb_space == DON_RGB4)
{
return ILLUMINANT_D50;
}
else if (rgb_space == ECI_RGB)
{
return ILLUMINANT_D50;
}
else if (rgb_space == EKTA_SPACE)
{
return ILLUMINANT_D50;
}
else if (rgb_space == NTSC_RGB)
{
return ILLUMINANT_C;
}
else if (rgb_space == PAL_RGB)
{
return ILLUMINANT_D65;
}
else if (rgb_space == PROPHOTO)
{
return ILLUMINANT_D50;
}
else if (rgb_space == SMPTE_C)
{
return ILLUMINANT_D65;
}
else if (rgb_space == SRGB)
{
return ILLUMINANT_D65;
}
else if (rgb_space == WIDE_GAMUT)
{
return ILLUMINANT_D50;
}
else
assert(false);
}
static Color4<T> RGBtoHSV(const Color4<T> & color)
{
double h,s,v;
RGBtoHSV(static_cast<double>(color[0]), static_cast<double>(color[1]),
static_cast<double>(color[2]), h,s,v);
Color4<T> c(h,s,v,0.0);
Color4<T> c(h,s,v,color[3]);
return c;
}
@ -1433,7 +1499,7 @@ public:
double r,g,b;
HSVtoRGB(static_cast<double>(color[0]), static_cast<double>(color[1]),
static_cast<double>(color[2]), r,g,b);
Color4<T> c(r,g,b,0.0);
Color4<T> c(r,g,b,color[3]);
return c;
}
@ -1501,54 +1567,109 @@ public:
}
static Color4<T> XYZtoRGB(const Color4<T> & color)
static Color4<T> XYZtoRGB(const Color4<T> & color, Illuminant src,
RGBSpaces dest, ConeResponse response = BRADFORD)
{
double r,g,b;
XYZtoRGB(static_cast<double>(color[0]), static_cast<double>(color[1]),
static_cast<double>(color[2]), r,g,b);
Color4<T>(r,g,b,0.0);
static_cast<double>(color[2]), src, r,g,b, dest, response);
Color4<T>(r,g,b,color[3]);
return c;
}
static void XYZtoRGB(double X, double Y, double Z, Illuminant src,
double &R, double &G, double &B, RGBSpaces space)
double &R, double &G, double &B, RGBSpaces space, ConeResponse response = BRADFORD)
{
double Xp, Yp, Zp;
chromaticAdaptation(X, Y, Z, src, Xp, Yp, Zp, refIlluminant(space));
chromaticAdaptation(X, Y, Z, src, Xp, Yp, Zp, refIlluminant(space), response);
int index = static_cast<int>(space) * 3 * 3;
X = Xp * XYZ2RGB(index) + Yp * XYZ2RGB(index+3) + Zp * XYZ2RGB(index+6);
Y = Yp * XYZ2RGB(index+1) + Yp * XYZ2RGB(index+4) + Zp * XYZ2RGB(index+7);
Z = Zp * XYZ2RGB(index+2) + Yp * XYZ2RGB(index+5) + Zp * XYZ2RGB(index+8);
double r = Xp * XYZ2RGB(index) + Yp * XYZ2RGB(index+3) + Zp * XYZ2RGB(index+6);
double g = Yp * XYZ2RGB(index+1) + Yp * XYZ2RGB(index+4) + Zp * XYZ2RGB(index+7);
double b = Zp * XYZ2RGB(index+2) + Yp * XYZ2RGB(index+5) + Zp * XYZ2RGB(index+8);
// Account for gamma correction
if (space == SRGB)
{
if (r > 0.0031308)
R = 1.055 * pow(r, 1.0/2.4) - 0.055;
else
R = 12.92 * r;
if (g > 0.0031308)
G = 1.055 * pow(g, 1.0/2.4) - 0.055;
else
G = 12.92 * g;
if (b > 0.0031308)
B = 1.055 * pow(b, 1.0/2.4) - 0.055;
else
B = 12.92 * b;
}
else
{
double lambda = gamma(space);
R = pow(r, 1.0/lambda);
G = pow(g, 1.0/lambda);
B = pow(b, 1.0/lambda);
}
}
static Color4<T> RGBtoXYZ(const Color4<T> & color)
static Color4<T> RGBtoXYZ(const Color4<T> & color, RGBSpaces space,
Illuminant dest, ConeResponse response = BRADFORD)
{
double x,y,z;
RGBtoXYZ(static_cast<double>(color[0]), static_cast<double>(color[1]),
static_cast<double>(color[2]), x,y,z);
Color4<T>(x,y,z,0.0);
static_cast<double>(color[2]), space, x,y,z, dest, response);
Color4<T> c(x,y,z,color[3]);
return c;
}
static void RGBtoXYZ(double R, double G, double B, RGBSpaces space,
double &X, double &Y, double &Z, Illuminant dest)
double &X, double &Y, double &Z, Illuminant dest, ConeResponse response = BRADFORD)
{
// Account for Gamma Correction
double r,g,b;
if (space == SRGB)
{
if (R <= 0.04045)
r = R / 12.92;
else
r = pow((R + 0.055) / 1.055, 2.4);
if (G <= 0.04045)
g = G / 12.92;
else
g = pow((G + 0.055) / 1.055, 2.4);
if (B <= 0.04045)
b = B / 12.92;
else
b = pow((B + 0.055) / 1.055, 2.4);
}
else
{
double lambda = gamma(space);
r = pow(R, lambda);
g = pow(G, lambda);
b = pow(B, lambda);
}
int index = static_cast<int>(space) * 3 * 3;
double Xt = R * RGB2XYZ(index) + G * RGB2XYZ(index+3) + B * RGB2XYZ(index+6);
double Yt = R * RGB2XYZ(index+1) + G * RGB2XYZ(index+4) + B * RGB2XYZ(index+7);
double Zt = R * RGB2XYZ(index+2) + G * RGB2XYZ(index+5) + B * RGB2XYZ(index+8);
double Xt = r * RGB2XYZ(index) + g * RGB2XYZ(index+3) + b * RGB2XYZ(index+6);
double Yt = r * RGB2XYZ(index+1) + g * RGB2XYZ(index+4) + b * RGB2XYZ(index+7);
double Zt = r * RGB2XYZ(index+2) + g * RGB2XYZ(index+5) + b * RGB2XYZ(index+8);
// Convert from reference illuminant to the desired one
chromaticAdaptation(Xt, Yt, Zt, refIlluminant(space), X, Y, Z, dest);
chromaticAdaptation(Xt, Yt, Zt, refIlluminant(space), X, Y, Z, dest, response);
}
static Color4<T> XYZtoCIELab(const Color4<T> & color)
static Color4<T> XYZtoCIELab(const Color4<T> & color, Illuminant ref)
{
double L,a,b;
XYZtoCIELab(static_cast<double>(color[0]), static_cast<double>(color[1]),
static_cast<double>(color[2]), L,a,b);
Color4<T>(L,a,b,0.0);
static_cast<double>(color[2]), L,a,b, ref);
Color4<T> c(L,a,b,color[3]);
return c;
}
@ -1590,12 +1711,12 @@ public:
b = 200.0 * (fy - fz);
}
static Color4<T> CIELabtoXYZ(const Color4<T> & color)
static Color4<T> CIELabtoXYZ(const Color4<T> & color, Illuminant ref)
{
double x,y,z;
CIELabtoXYZ(static_cast<double>(color[0]), static_cast<double>(color[1]),
static_cast<double>(color[2]), x,y,z);
Color4<T>(x,y,z,0.0);
Color4<T>(x,y,z,color[3]);
return c;
}
@ -1656,7 +1777,7 @@ public:
double h,s,l;
RGBtoHSL(static_cast<double>(color[0]), static_cast<double>(color[1]),
static_cast<double>(color[2]), h,s,l);
Color4<T>(h,s,l,0.0);
Color4<T>(h,s,l,color[3]);
return c;
}
@ -1709,7 +1830,7 @@ public:
double r,g,b;
HSLtoRGB(static_cast<double>(color[0]), static_cast<double>(color[1]),
static_cast<double>(color[2]), r,g,b);
Color4<T>(r,g,b,0.0);
Color4<T>(r,g,b,color[3]);
return c;
}
@ -1764,7 +1885,7 @@ public:
xyYtoXYZ(static_cast<double>(color[0]), static_cast<double>(color[1]),
static_cast<double>(color[2]), X,Y,Z));
Color4<T>(X,Y,Z,0.0);
Color4<T>(X,Y,Z,color[3]);
return c;
}
@ -1793,17 +1914,18 @@ public:
Y = _Y;
}
// XYZ (Illuminant src) --> XYZ (Illuminant dest) - [ILLUMINANT CHANGE]
static Color4<T> chromaticAdaptation(const Color4<T> & color, Illuminant src,
Illuminant dst, ConeResponse response = BRADFORD)
{
double X,Y,Z;
chromaticAdaptation(static_cast<double>(color[0]), static_cast<double>(color[1]),
static_cast<double>(color[2]), src, X, Y, Z, dst, response);
Color4<T>(X,Y,Z,0.0);
Color4<T> c(X,Y,Z,color[3]);
return c;
}
// XYZ (Illuminant src) --> XYZ (Illuminant dst) - [ILLUMINANT CHANGE]
// XYZ (Illuminant src) --> XYZ (Illuminant dest) - [ILLUMINANT CHANGE]
static void chromaticAdaptation(double _X, double _Y, double _Z, Illuminant src,
double &X, double &Y, double &Z, Illuminant dst, ConeResponse response = BRADFORD)
{
@ -1814,6 +1936,27 @@ public:
Y = CA(index+1) * _X + CA(index+4) * _Y + CA(index+7) * _Z;
Z = CA(index+2) * _X + CA(index+5) * _Y + CA(index+8) * _Z;
}
// RGB (working space src) --> RGB (working space dest) - [RGB WORKING SPACE CHANGE]
static Color4<T> RGBtoRGB(const Color4<T> & color, RGBSpaces src, RGBSpaces dest,
ConeResponse response = BRADFORD)
{
double R,G,B;
RGBtoRGB(static_cast<double>(color[0]), static_cast<double>(color[1]),
static_cast<double>(color[2]), src, R,G,B, dest, response);
Color4<T> c(R,G,B,color[3]);
return c;
}
// RGB (working space src) --> RGB (working space dest) - [RGB WORKING SPACE CHANGE]
static void RGBtoRGB(double _R, double _G, double _B, RGBSpaces src,
double &R, double &G, double &B, RGBSpaces dest, ConeResponse response = BRADFORD)
{
double X,Y,Z;
RGBtoXYZ(_R, _G, _B, src, X,Y,Z, refIlluminant(src));
XYZtoRGB(X,Y,Z, refIlluminant(src), R,G,B, dest);
}
};