颜色值之间的转换js代码。
十六进制与RGB转换：
//十六进制颜色值的正则表达式
var reg = /^#([0-9a-fA-f]{3}|[0-9a-fA-f]{6})$/;
/*RGB颜色转换为16进制*/
String.prototype.colorHex = function(){
var that = this;
if(/^(rgb|RGB)/.test(that)){
var aColor = that.replace(/(?:\(|\)|rgb|RGB)*/g,"").split(",");
var strHex = "#";
for(var i=0; i<aColor.length; i++){
var hex = Number(aColor[i]).toString(16);
if(hex === "0"){
hex += hex;
}
strHex += hex;
}
if(strHex.length !== 7){
strHex = that;
}
return strHex;
}else if(reg.test(that)){
var aNum = that.replace(/#/,"").split("");
if(aNum.length === 6){
return that;
}else if(aNum.length === 3){
var numHex = "#";
for(var i=0; i<aNum.length; i+=1){
numHex += (aNum[i]+aNum[i]);
}
return numHex;
}
}else{
return that;
}
};
//-------------------------------------------------
/*16进制颜色转为RGB格式*/
String.prototype.colorRgb = function(){
var sColor = this.toLowerCase();
if(sColor && reg.test(sColor)){
if(sColor.length === 4){
var sColorNew = "#";
for(var i=1; i<4; i+=1){
sColorNew += sColor.slice(i,i+1).concat(sColor.slice(i,i+1));
}
sColor = sColorNew;
}
//处理六位的颜色值
var sColorChange = [];
for(var i=1; i<7; i+=2){
sColorChange.push(parseInt("0x"+sColor.slice(i,i+2)));
}
return "RGB(" + sColorChange.join(",") + ")";
}else{
return sColor;
}
};
HSL转RGB
/**
* HSL颜色值转换为RGB.
* 换算公式改编自 http://en.wikipedia.org/wiki/HSL_color_space.
* h, s, 和 l 设定在 [0, 1] 之间
* 返回的 r, g, 和 b 在 [0, 255]之间
*
* @param Number h 色相
* @param Number s 饱和度
* @param Number l 亮度
* @return Array RGB色值数值
*/
function hslToRgb(h, s, l){
var r, g, b;
if(s == 0){
r = g = b = l; // achromatic
}else{
var hue2rgb = function hue2rgb(p, q, t){
if(t < 0) t += 1;
if(t > 1) t -= 1;
if(t < 1/6) return p + (q - p) * 6 * t;
if(t < 1/2) return q;
if(t < 2/3) return p + (q - p) * (2/3 - t) * 6;
return p;
}
var q = l < 0.5 ? l * (1 + s) : l + s - l * s;
var p = 2 * l - q;
r = hue2rgb(p, q, h + 1/3);
g = hue2rgb(p, q, h);
b = hue2rgb(p, q, h - 1/3);
}
return [Math.round(r * 255), Math.round(g * 255), Math.round(b * 255)];
}
RGB转HSL
/**
* RGB 颜色值转换为 HSL.
* 转换公式参考自 http://en.wikipedia.org/wiki/HSL_color_space.
* r, g, 和 b 需要在 [0, 255] 范围内
* 返回的 h, s, 和 l 在 [0, 1] 之间
*
* @param Number r 红色色值
* @param Number g 绿色色值
* @param Number b 蓝色色值
* @return Array HSL各值数组
*/
function rgbToHsl(r, g, b){
r /= 255, g /= 255, b /= 255;
var max = Math.max(r, g, b), min = Math.min(r, g, b);
var h, s, l = (max + min) / 2;
if(max == min){
h = s = 0; // achromatic
}else{
var d = max - min;
s = l > 0.5 ? d / (2 - max - min) : d / (max + min);
switch(max){
case r: h = (g - b) / d + (g < b ? 6 : 0); break;
case g: h = (b - r) / d + 2; break;
case b: h = (r - g) / d + 4; break;
}
h /= 6;
}
return [h, s, l];
}
参考：zxx
