en javascript?

j'ai trouvé ca sur http://javascriptfr.com/code.aspx?ID=17130(...)
en cherchant rgb2hsl via mon ami google :)

/ JScript source code

//Red : 0..255

//Green : 0..255

//Blue : 0..255

//Hue : 0,0..360,0<=>0..255

//Lum : 0,0..1,0<=>0..255

//Sat : 0,0..1,0<=>0..255



//Retourne un tableau de 3 valeurs : H,S,L

function RGB2HSL (r, g, b)

{

 red = Math.round (r);

 green = Math.round (g);

 blue = Math.round (b);

 var minval = Math.min (red, Math.min (green, blue));

 var maxval = Math.max (red, Math.max (green, blue));

 var mdiff = maxval - minval + 0.0;

 var msum = maxval + minval + 0.0;

 var luminance = msum / 510.0;

 var saturation;

 var hue;

 if (maxval == minval)

 {

 saturation = 0.0;

 hue = 0.0;

 }

 else

 {

 var rnorm = (maxval - red) / mdiff;

 var gnorm = (maxval - green) / mdiff;

 var bnorm = (maxval - blue) / mdiff;

 saturation = (luminance <= 0.5) ? (mdiff / msum) : (mdiff / (510.0 - msum));

 if (red == maxval)

 hue = 60.0 * (6.0 + bnorm - gnorm);

 if (green == maxval)

 hue = 60.0 * (2.0 + rnorm - bnorm);

 if (blue == maxval)

 hue = 60.0 * (4.0 + gnorm - rnorm);

 if (hue > 360.0)

 hue -= 360.0;

 }

 return new Array (Math.round (hue * 255.0 / 360.0), Math.round (saturation * 255.0), Math.round (luminance * 255.0));

}



function Magic (rm1, rm2, rh)

{

 var retval = rm1;

 if (rh > 360.0)

 rh -= 360.0;

 if (rh < 0.0)

 rh += 360.0;

 if (rh < 60.0)

 retval = rm1 + (rm2 - rm1) * rh / 60.0;

 else if (rh < 180.0)

 retval = rm2;

 else if (rh < 240.0)

 retval = rm1 + (rm2 - rm1) * (240.0 - rh) / 60.0;

 return Math.round (retval * 255);

}



//Retourne un tableau de 3 valeurs : R,G,B

function HSL2RGB (h, s, l)

{

 var hue = h * 360.0 / 255.0;

 var saturation = s / 255.0;

 var luminance = l / 255.0;

 var red;

 var green;

 var blue;

 if (saturation == 0.0)

 {

 red = green = blue = Math.round (luminance * 255.0);

 }

 else

 {

 var rm1;

 var rm2;

 if (luminance <= 0.5)

 rm2 = luminance + luminance * saturation;

 else

 rm2 = luminance + saturation - luminance * saturation;

 rm1 = 2.0 * luminance - rm2;

 red = Magic (rm1, rm2, hue + 120.0);

 green = Magic (rm1, rm2, hue);

 blue = Magic (rm1, rm2, hue - 120.0);

 }

 return new Array (red, green, blue);

}