Prototype ¬ Detail

author: Prometh [+], Submitted: 12.02.03 12p • Last Edit: 12.02.03 1p

Color.RGBtoHSB = function(r,g,b) {
	var hsb = new Object();
	hsb.b = Math.max(Math.max(r,g),b);
	var min = Math.min(Math.min(r,g),b);
	hsb.s = (hsb.b <= 0) ? 0 : Math.round(100*(hsb.b - min)/hsb.b);
	hsb.b = Math.round((hsb.b /255)*100);
	hsb.h = 0;
	if((r==g) && (g==b))  hsb.h = 0;
	else if(r>=g && g>=b) hsb.h = 60*(g-b)/(r-b);
	else if(g>=r && r>=b) hsb.h = 60  + 60*(g-r)/(g-b);
	else if(g>=b && b>=r) hsb.h = 120 + 60*(b-r)/(g-r);
	else if(b>=g && g>=r) hsb.h = 180 + 60*(b-g)/(b-r);
	else if(b>=r && r>=g) hsb.h = 240 + 60*(r-g)/(b-g);
	else if(r>=b && b>=g) hsb.h = 300 + 60*(r-b)/(r-g);
	else hsb.h = 0;
	hsb.h = Math.round(hsb.h);
	return hsb;
}

usage

// This is a cleaned up version of Luzifer Altenberg's script. He gets the most credit
// You can compare these values to those produced in the Photoshop Color Picker

r = 255;
g = 50;
b = 120;
hsb = RGBtoHSB(r,g,b);

trace(hsb.h);   // outputs a scale of 0-360 (degrees)
trace(hsb.s);   // outputs a scale of 0-100 (percent)
trace(hsb.b);   // same as above