颜色空间转化c++代码

rgb转grey：

void RgbToGrey(unsigned char *rgb, double *grey) 

{

  double R = ((double) rgb[0]) / (double)255.0;

  double G = ((double) rgb[1]) / (double)255.0;

  double B = ((double) rgb[2]) / (double)255.0;

  double y = (double)0.212671 * R + (double)0.715160 * G + (double)0.072169 * B;

  if (y > (double)0.008856) {

    grey[0] = (double)116.0 * pow(y, (double)1.0 / (double)3.0) - (double)16.0;

  }

  else {

    grey[0] = (double)903.3 * y;

  }

}

rgb转lvu:

void RgbToLuv(unsigned char *rgb, double *luv)

{

  double L, u, v;

  double R = ((double) rgb[0]) / (double)255.0;

  double G = ((double) rgb[1]) / (double)255.0;

  double B = ((double) rgb[2]) / (double)255.0;

  double x = (double)0.412453 * R + (double)0.357580 * G + (double)0.180423 * B;

  double y = (double)0.212671 * R + (double)0.715160 * G + (double)0.072169 * B;

  double z = (double)0.019334 * R + (double)0.119193 * G + (double)0.950227 * B;

  if (y > 0.008856) {

    L = (double)116.0 * pow(y, (double)1.0 / (double)3.0) - (double)16.0;

  }

  else {

    L = (double)903.3 * y;

  }

  double sum = x + 15 * y + 3 * z;

  if (sum != 0) {

    u = 4 * x / sum, v = 9 * y / sum;

  }

  else {

    u = 4.0, v = (double)9.0 / (double)15.0;

  }

  luv[0] = L;

  luv[1] = 13 * L * (u - (double)0.19784977571475);

  luv[2] = 13 * L * (v - (double)0.46834507665248);

}

rgb转lab：

void RgbToLab(unsigned char *rgb, double *lab)

{

  double R = ((double) rgb[0]) / (double)255.0;

  double G = ((double) rgb[1]) / (double)255.0;

  double B = ((double) rgb[2]) / (double)255.0;

  double X =  0.412453 * R + 0.357580 * G + 0.180423 * B;

  double Y =  0.212671 * R + 0.715160 * G + 0.072169 * B;

  double Z =  0.019334 * R + 0.119193 * G + 0.950227 * B;

  double xr = X / 0.950456, yr = Y / 1.000, zr = Z / 1.088854;

  if (yr > 0.008856) {

    lab[0] = 116.0 * pow(yr, 1.0 / 3.0) - 16.0;

  }

  else {

    lab[0] = 903.3 * yr;

  }

  double fxr, fyr, fzr;

  if (xr > 0.008856) {

    fxr = pow(xr, 1.0 / 3.0);

  }

  else {

    fxr = 7.787 * xr + 16.0 / 116.0;

  }

  if (yr > 0.008856) {

    fyr = pow(yr, 1.0 / 3.0);

  }

  else {

    fyr = 7.787 * yr + 16.0 / 116.0;

  }

  if(zr > 0.008856) {

    fzr = pow(zr, 1.0 / 3.0);

  }

  else {

    fzr = 7.787 * zr + 16.0 / 116.0;

  }

  lab[1] = 500.0 * (fxr - fyr);

  lab[2] = 200.0 * (fyr - fzr);

}

grey转rgb：

void GreyToRgb(double *grey, unsigned char *rgb)

{

  if (grey[0] < (double)0.1) {

    rgb[0] = rgb[1] = rgb[2] = 0;

  }

  else {

    double y;

    if(grey[0] <= (double)7.9996) {

      y = 255 * grey[0] / (double)903.3;

    }

    else {

      y = (grey[0] + (double)16.0) / (double)116.0, y  = 255 * y * y * y;

    }

    rgb[0] = (unsigned char)((y < 0) ? 0 : ((y > 255) ? 255 : y));

    rgb[2] = rgb[1] = rgb[0];

  }

}

grey转luv：

void GreyToLuv(double *grey, double *luv)

{

  luv[0] = grey[0], luv[1] = luv[2] = 0;

}

grey转lab：

void GreyToLab(double *grey, double *lab)

{

  lab[0] = grey[0], lab[1] = lab[2] = 0;

}

luv转rgb：

void LuvToRgb(double *luv, unsigned char *rgb)

{

  if (luv[0] < 0.1) {

    rgb[0] = rgb[1] = rgb[2] = 0;

  }

  else {

    double x, y, z, u, v;

    if (luv[0] <= (double)7.9996) {

      y = luv[0] / (double)903.3;

    }

    else {

      y = (luv[0] + (double)16.0) / (double)116.0, y  = y * y * y;

    }

    u = luv[1] / (13 * luv[0]) + (double)0.19784977571475;

    v = luv[2] / (13 * luv[0]) + (double)0.46834507665248;

    x = 9 * u * y / (4 * v);

    z = (12 - 3 * u - 20 * v) * y / (4 * v);

    double R = (double)3.240479 * x - (double)1.537150 * y - (double)0.498535 * z;

    double G = (double)-0.969256 * x + (double)1.875992 * y + (double)0.041556 * z;

    double B = (double)0.055648 * x - (double)0.204043 * y + (double)1.057311 * z;

    R *= 255, G *= 255, B *= 255;

    rgb[0] = (unsigned char)((R < 0) ? 0 : ((R > 255) ? 255 : R));

    rgb[1] = (unsigned char)((G < 0) ? 0 : ((G > 255) ? 255 : G));

    rgb[2] = (unsigned char)((B < 0) ? 0 : ((B > 255) ? 255 : B));

  }

}

luv转grey：

void LuvToGrey(double *luv, double *grey)

{

  grey[0] = luv[0];

}

lab转rgb：

void LabToRgb(double *lab, unsigned char *rgb)

{

  double X, Y, Z;

  double P = (lab[0] + 16.0) / 116.0;

  if (lab[0] > 7.9996) {

    Y = 1.000 * P * P * P;

  }

  else {

    Y = 1.000 * lab[0] / 903.3;

  }

  double yr = Y / 1.000, fy;

  if (yr > 0.008856) {

    fy = pow(yr, 1.0 / 3.0);

  }

  else {

    fy = 7.787 * yr + 16.0 / 116.0;

  }

  double fx = lab[1] / 500.0 + fy, fz = fy - lab[2] / 200.0;

  if(fx > 0.2069) {

    X = 0.950456 * fx * fx * fx;

  }

  else {

    X = 0.950456 / 7.787 * (fx - 16.0 / 116.0);

  }

  if (fz > 0.2069) {

    Z = 1.088854 * fz * fz * fz;

  }

  else {

    Z = 1.088854 / 7.787 * (fz - 16.0 / 116.0);

  }

  double R = 3.240479 * X - 1.537150 * Y - 0.498535 * Z;

  double G = -0.969256 * X + 1.875992 * Y + 0.041556 * Z;

  double B = 0.055648 * X - 0.204043 * Y + 1.057311 * Z;

  R *= 255, G *= 255, B *= 255;

  rgb[0] = (unsigned char)((R < 0) ? 0 : ((R > 255) ? 255 : R));

  rgb[1] = (unsigned char)((G < 0) ? 0 : ((G > 255) ? 255 : G));

  rgb[2] = (unsigned char)((B < 0) ? 0 : ((B > 255) ? 255 : B));

}

lab转grey：

void LabToGrey(double *lab, double *grey)

{

  grey[0] = lab[0];

}