// RGB转换为YUV
void RGB2YUV(double R, double G, double B, double &Y, double &U, double &V)
{
Y = static_cast<double>(0.257*R + 0.504*G + 0.098*B + 16); // y
U = static_cast<double>(-0.148*R - 0.291*G+ 0.439*B + 128); // u
V = static_cast<double>(0.439*R - 0.368*G - 0.071*B + 128); // v
}
// YUV转换为RGB
void YUV2RGB(double Y,double U,double V, double &R, double &G, double &B)
{
R = static_cast<double>(1.0*Y + 8 + 1.402*(V-128)); // r
G = static_cast<double>(1.0*Y - 0.34413*(U-128) - 0.71414*(V-128));
B = static_cast<double>(1.0*Y + 1.772*(U-128) + 0);
}
// RGB转换为XYZ
void RGB2XYZ(double r, double g, double b double &x, double &y, double &z)
{
double var_R,var_G,var_B;
var_R = (r / 255.0f);
var_G = (g / 255.0f);
var_B = (b / 255.0f);
if (var_R > 0.04045)
{
var_R = pow((var_R + 0.055)/1.055, 2.4);
}
else
{
var_R = var_R / 12.92;
}
if (var_G > 0.04045)
{
var_G = pow((var_G + 0.055)/1.055, 2.4);
}
else
{
var_G = var_G / 12.92;
}
if (var_B > 0.04045)
{
var_B = pow((var_B + 0.055)/1.055, 2.4);
}
else
{
var_B = var_B / 12.92;
}
var_R = var_R * 100.0f;
var_G = var_G * 100.0f;
var_B = var_B * 100.0f;
//Observer. = 2°, Illuminant = D65
x = var_R * 0.4124 + var_G * 0.3576 + var_B * 0.1805;
y = var_R * 0.2126 + var_G * 0.7152 + var_B * 0.0722;
z = var_R * 0.0193 + var_G * 0.1192 + var_B * 0.9505;
}
// XYZ转换为LAB
void XYZ2LAB(double x, double y, double z, double &L, double &A ,double &B)
{
double var_X,var_Y,var_Z;
var_X = x / 95.047f;
var_Y = y / 100.000f;
var_Z = z / 108.883f;
if ( var_X > 0.008856 )
{
var_X = pow((float)var_X,1.0f/3.0f);
}
else
{
var_X = ( 7.787 * var_X ) + ( 16 / 116 );
}
if (var_Y > 0.008856)
{
var_Y = pow((float)var_Y,1.0f/3.0f);
}
else
{
var_Y = ( 7.787 * var_Y ) + ( 16 / 116 );
}
if ( var_Z > 0.008856 )
{
var_Z = pow((float)var_Z,1.0f/3.0f);
}
else
{
var_Z = ( 7.787 * var_Z ) + ( 16 / 116 );
}
L = ( 116 * var_Y ) - 16;
A = 500 * ( var_X - var_Y );
B = 200 * ( var_Y - var_Z );
}
// RGB转换为LAB
void RGB2LAB(double r, double g,double b, double &L, double &A, double &B)
{
double x,y,z;
RGB2XYZ(r,g,b,x,y,z);
XYZ2LAB(x,y,z,L,A,B);
}
// LAB转换为RGB
void LAB2RGB(double L, double A, double B, double &R, double &G, double &B)
{
double x,y,z[3];
this->LAB2XYZ(L,A,B,x,y,z);
this->XYZ2RGB(x,y,z,R,G,B);
}
// LAB转换为XYZ
void LAB2XYZ(double lab_L, double lab_A, double lab_B, double &X, double &Y, double &Z)
{
double var_X,var_Y, var_Z;
var_Y = ( lab_L + 16 ) / 116;
var_X = lab_A / 500 + var_Y;
var_Z = var_Y - lab_B / 200;
if ( pow((double)var_Y,3) > 0.008856 )
var_Y = pow((double)var_Y,3);
else
var_Y = ( var_Y - 16 / 116 ) / 7.787;
if ( pow((double)var_X,3) > 0.008856 )
var_X = pow((double)var_X,3);
else
var_X = ( var_X - 16 / 116 ) / 7.787;
if ( pow((double)var_Z,3) > 0.008856 )
var_Z = pow((double)var_Z,3);
else
var_Z = ( var_Z - 16 / 116 ) / 7.787;
X = 95.047 * var_X;
Y = 100.000 * var_Y;
Z = 108.883 * var_Z;
}
// XYZ转换为RGB
void XYZ2RGB(double x, double y, double z, double &R, double &G, double &B)
{
double var_X,var_Y,var_Z,var_R,var_G,var_B;
double x,y,z;
var_X = x / 100.0f; //X from 0 to 95.047 (Observer = 2°, Illuminant = D65)
var_Y = y / 100.0f; //Y from 0 to 100.000
var_Z = z / 100.0f; //Z from 0 to 108.883
var_R = var_X * 3.2406 + var_Y * -1.5372 + var_Z * -0.4986;
var_G = var_X * -0.9689 + var_Y * 1.8758 + var_Z * 0.0415;
var_B = var_X * 0.0557 + var_Y * -0.2040 + var_Z * 1.0570;
if ( var_R > 0.0031308 )
var_R = 1.055 * ( pow(var_R,( 1 / 2.4 ) )) - 0.055;
else
var_R = 12.92 * var_R;
if ( var_G > 0.0031308 )
var_G = 1.055 * ( pow(var_G, ( 1 / 2.4 )) ) - 0.055;
else
var_G = 12.92 * var_G;
if ( var_B > 0.0031308 )
var_B = 1.055 * ( pow(var_B, ( 1 / 2.4 )) ) - 0.055;
else
var_B = 12.92 * var_B;
R = var_R * 255.0f;
G = var_G * 255.0f;
b = var_B * 255.0f;
}
// RGB转换为HSV
void RGB2HSV(double R, double G, double B, double &H, double &S, double V)
{
double var_R,var_G,var_B;
var_R = ( R / 255 ); //RGB from 0 to 255
var_G = ( G / 255 );
var_B = ( B / 255 );
double var_Min,var_Max,del_Max;
var_Min = min(min(var_R,var_G),var_B);
var_Max = max(max(var_R,var_G),var_B);
del_Max = var_Max - var_Min; //Delta RGB value
double H,S,V;
V = var_Max;
if ( del_Max == 0 ) //This is a gray, no chroma
{
H = 0; //HSV results from 0 to 1
S = 0;
}
else //Chromatic data
{
S = del_Max / var_Max;
double del_R,del_G,del_B;
del_R = ( ( ( var_Max - var_R ) / 6 ) + ( del_Max / 2 ) ) / del_Max;
del_G = ( ( ( var_Max - var_G ) / 6 ) + ( del_Max / 2 ) ) / del_Max;
del_B = ( ( ( var_Max - var_B ) / 6 ) + ( del_Max / 2 ) ) / del_Max;
if ( var_R == var_Max )
H = del_B - del_G;
else if ( var_G == var_Max )
H = ( 1 / 3 ) + del_R - del_B;
else if ( var_B == var_Max )
H = ( 2 / 3 ) + del_G - del_R;
if ( H < 0 )
H += 1;
if ( H > 1 )
H -= 1;
}
}
// HSV转换为RGB
void HSV2RGB(double H, double S, double V, double &R, double &G, double &B)
{
double R,G,B;
if ( S == 0 ) //HSV from 0 to 1
{
R = V * 255.0f;
G = V * 255.0f;
B = V * 255.0f;
}
else
{
double var_h,var_i,var_1,var_2,var_3;
var_h = H * 6.0f;
if ( var_h == 6 )
var_h = 0; //H must be < 1
var_i = int( var_h ); //Or var_i = floor( var_h )
var_1 = V * ( 1 - S );
var_2 = V * ( 1 - S * ( var_h - var_i ) );
var_3 = V * ( 1 - S * ( 1 - ( var_h - var_i ) ) );
double var_r,var_g,var_b;
if ( var_i == 0 )
{
var_r = V;
var_g = var_3 ;
var_b = var_1;
}
else if ( var_i == 1 )
{
var_r = var_2 ;
var_g = V;
var_b = var_1;
}
else if ( var_i == 2 )
{
var_r = var_1 ;
var_g = V;
var_b = var_3;
}
else if ( var_i == 3 )
{
var_r = var_1 ;
var_g = var_2 ;
var_b = V;
}
else if ( var_i == 4 )
{
var_r = var_3 ;
var_g = var_1 ;
var_b = V;
}
else
{
var_r = V;
var_g = var_1 ;
var_b = var_2;
}
R = var_r * 255.0f; //RGB results from 0 to 255
G = var_g * 255.0f;
B = var_b * 255.0f;
}
}
// YUV转换为XYZ
void YUV2XYZ(double L, double U, double V, double &X, double &Y, double &Z)
{
double var_Y,ref_X,ref_Y,ref_Z,ref_U,ref_V,var_U,var_V;
var_Y = ( L + 16 ) / 116;
if ( pow(var_Y,3) > 0.008856 )
var_Y = pow(var_Y,3);
else
var_Y = ( var_Y - 16 / 116 ) / 7.787;
ref_X = 95.047; //Observer= 2°, Illuminant= D65
ref_Y = 100.000;
ref_Z = 108.883;
ref_U = ( 4 * ref_X ) / ( ref_X + ( 15 * ref_Y ) + ( 3 * ref_Z ) );
ref_V = ( 9 * ref_Y ) / ( ref_X + ( 15 * ref_Y ) + ( 3 * ref_Z ) );
var_U = U / ( 13 * L ) + ref_U;
var_V = V / ( 13 * L) + ref_V;
Y = var_Y * 100;
X = - ( 9 * Y * var_U ) / ( ( var_U - 4 ) * var_V - var_U * var_V );
Z = ( 9 * Y - ( 15 * var_V * Y ) - ( var_V * X ) ) / ( 3 * var_V );
}
// LAB转换为HSV
void LAB2HSV(double L, double A, double B, double &H, double &S, double &V)
{
double X,Y,Z;
this->LAB2XYZ(L,A,B,X,Y,Z);
this->XYZ2HSV(X,Y,Z,H,S,V);
}
// XYZ转换为HSV
void XYZ2HSV(double X, double Y, double Z,double &H, double &S, double &V)
{
double R,G,B;
this->XYZ2RGB(X,Y,Z,R,G,B);
this->RGB2HSV(R,G,B,H,S,V);
}
// RGB转换为CMY
void RGB2CMY(double R, double G, double B, double &C, double &M, double Y)
{
C = 1.0 - ( R / 255.0f );
M = 1.0 - ( G / 255.0f );
Y = 1.0 - ( B / 255.0f );
}
//CMY转换为RGB
void CMY2RGB(double C, double M, double Y, double &R, double &G, double &B)
{
R = ( 1.0f - C ) * 255.0f;
G = ( 1.0f - M ) * 255.0f;
B = ( 1.0f - Y ) * 255.0f;
}
//RGB转换为CMYK
void RGB2CMYK(double R, double G, double B, double &C, double &M, double Y, double &K)
{
double bufCMY[3];
//RGB2CMY
this->RGB2CMY(R,G,B,C,M,Y);
//CMYK and CMY values from 0 to 1
double var_K;
var_K = 1;
if ( C < var_K )
var_K = C;
if ( M < var_K )
var_K = M;
if ( Y < var_K )
var_K = Y;
if ( var_K == 1 )
{ //Black
C = 0;
M = 0;
Y = 0;
}
else
{
C = ( C - var_K ) / ( 1 - var_K );
M = ( M - var_K ) / ( 1 - var_K );
Y = ( Y - var_K ) / ( 1 - var_K );
}
K = var_K;
}
//CMYK转换为CMY
void CMYK2CMY(double C1, double M1, double Y1, double K1, double &C2, double &M2, double Y2)
{
C2 = ( C1 * ( 1 - K1 ) + K1 );
M2 = ( M1 * ( 1 - K1 ) + K1 );
Y2 = ( Y1 * ( 1 - K1 ) + K1 );
}
复制代码
本文转自Phinecos(洞庭散人)博客园博客，原文链接：http://www.cnblogs.com/phinecos/archive/2009/05/03/1448121.html，如需转载请自行联系原作者
