我正在寻找一个算法之间的HSL颜色转换为RGB。
在我看来，HSL不是很广泛地使用，所以我没有太多的运气寻找一个转换器。
当前回答
当你需要RGB到HSV，反之亦然:
function rgbToHsv(r, g, b)
{
r /= 255, g /= 255, b /= 255;
var min = Math.min(r, g, b),
max = Math.max(r, g, b),
delta = max - min,
h = 0, s = 0, v = max;
if (min != max)
{
s = (delta / max);
switch (max)
{
case r: h = (g - b) / delta + (g < b ? 6 : 0); break;
case g: h = (b - r) / delta + 2; break;
case b: h = (r - g) / delta + 4; break;
}
h /= 6;
}
return [h, s, v];
}
function hsvToRgb(h, s, v)
{
var step = h / (1 / 6),
pos = step - Math.floor(step), // the hue position within the current step
m = (Math.floor(step) % 2) ? (1 - pos) * v : pos * v, // mix color value adjusted to the brightness(v)
max = 1 * v,
min = (1 - s) * v,
med = m + ((1 - s) * (v - m)),
r, g, b;
switch (Math.floor(step))
{
case 0:
r = max;
g = med;
b = min;
break;
case 1:
r = med;
g = max;
b = min;
break;
case 2:
r = min;
g = max;
b = med;
break;
case 3:
r = min;
g = med;
b = max;
break;
case 4:
r = med;
g = min;
b = max;
break;
case 5:
r = max;
g = min;
b = med;
break;
}
return [Math.round(r * 255), Math.round(g * 255), Math.round(b * 255)];
}
其他回答
这里是修改后的javascript函数，它在0-360度集输出Hue。
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 ; break;
case g: h = 2 + ( (b - r) / d); break;
case b: h = 4 + ( (r - g) / d); break;
}
h*=60;
if (h < 0) h +=360;
}
return([h, s, l]);
}
alert(rgbToHsl(125,115,145));
当你需要RGB到HSV，反之亦然:
function rgbToHsv(r, g, b)
{
r /= 255, g /= 255, b /= 255;
var min = Math.min(r, g, b),
max = Math.max(r, g, b),
delta = max - min,
h = 0, s = 0, v = max;
if (min != max)
{
s = (delta / max);
switch (max)
{
case r: h = (g - b) / delta + (g < b ? 6 : 0); break;
case g: h = (b - r) / delta + 2; break;
case b: h = (r - g) / delta + 4; break;
}
h /= 6;
}
return [h, s, v];
}
function hsvToRgb(h, s, v)
{
var step = h / (1 / 6),
pos = step - Math.floor(step), // the hue position within the current step
m = (Math.floor(step) % 2) ? (1 - pos) * v : pos * v, // mix color value adjusted to the brightness(v)
max = 1 * v,
min = (1 - s) * v,
med = m + ((1 - s) * (v - m)),
r, g, b;
switch (Math.floor(step))
{
case 0:
r = max;
g = med;
b = min;
break;
case 1:
r = med;
g = max;
b = min;
break;
case 2:
r = min;
g = max;
b = med;
break;
case 3:
r = min;
g = med;
b = max;
break;
case 4:
r = med;
g = min;
b = max;
break;
case 5:
r = max;
g = min;
b = med;
break;
}
return [Math.round(r * 255), Math.round(g * 255), Math.round(b * 255)];
}
HSL到RGB的Typescript
以上所有选项都不能在我的代码在TS工作。
我调整了其中一个，现在它就像一个咒语:
type HslType = { h: number; s: number; l: number }
const hslToRgb = (hsl: HslType): RgbType => {
let { h, s, l } = hsl
// IMPORTANT if s and l between 0,1 remove the next two lines:
s /= 100
l /= 100
const k = (n: number) => (n + h / 30) % 12
const a = s * Math.min(l, 1 - l)
const f = (n: number) =>
l - a * Math.max(-1, Math.min(k(n) - 3, Math.min(9 - k(n), 1)))
return {
r: Math.round(255 * f(0)),
g: Math.round(255 * f(8)),
b: Math.round(255 * f(4)),
}
}
我需要一个非常轻的重量，它不是100%，但它足够接近一些用例。
float3 Hue(float h, float s, float l)
{
float r = max(cos(h * 2 * UNITY_PI) * 0.5 + 0.5, 0);
float g = max(cos((h + 0.666666) * 2 * UNITY_PI) * 0.5 + 0.5, 0);
float b = max(cos((h + 0.333333) * 2 * UNITY_PI) * 0.5 + 0.5, 0);
float gray = 0.2989 * r + 0.5870 * g + 0.1140 * b;
return lerp(gray, float3(r, g, b), s) * smoothstep(0, 0.5, l) + 1 * smoothstep(0.5, 1, l);
}
Chris的c#代码的Php实现
也是从这里，这很好地解释了它的数学原理。
这基本上是一堆转换HSL(色相饱和度亮度)的函数
在PHP 5.6.15上测试并使用
TL;DR:完整的代码可以在Pastebin上找到。
##Hex to HSL 输入:十六进制颜色，格式:[#]0f4或[#]00ff44(磅号可选) 输出:HSL的程度，百分比，百分比
/**
* Input: hex color
* Output: hsl(in ranges from 0-1)
*
* Takes the hex, converts it to RGB, and sends
* it to RGBToHsl. Returns the output.
*
*/
function hexToHsl($hex) {
$r = "";
$g = "";
$b = "";
$hex = str_replace('#', '', $hex);
if (strlen($hex) == 3) {
$r = substr($hex, 0, 1);
$r = $r . $r;
$g = substr($hex, 1, 1);
$g = $g . $g;
$b = substr($hex, 2, 1);
$b = $b . $b;
} elseif (strlen($hex) == 6) {
$r = substr($hex, 0, 2);
$g = substr($hex, 2, 2);
$b = substr($hex, 4, 2);
} else {
return false;
}
$r = hexdec($r);
$g = hexdec($g);
$b = hexdec($b);
$hsl = rgbToHsl($r,$g,$b);
return $hsl;
}
RGB到HSL
输入:RGB，范围0-255 输出:HSL的程度，百分比，百分比。
/**
*
*Credits:
* https://stackoverflow.com/questions/4793729/rgb-to-hsl-and-back-calculation-problems
* http://www.niwa.nu/2013/05/math-behind-colorspace-conversions-rgb-hsl/
*
* Called by hexToHsl by default.
*
* Converts an RGB color value to HSL. Conversion formula
* adapted from http://www.niwa.nu/2013/05/math-behind-colorspace-conversions-rgb-hsl/.
* Assumes r, g, and b are contained in the range [0 - 255] and
* returns h, s, and l in the format Degrees, Percent, Percent.
*
* @param Number r The red color value
* @param Number g The green color value
* @param Number b The blue color value
* @return Array The HSL representation
*/
function rgbToHsl($r, $g, $b){
//For the calculation, rgb needs to be in the range from 0 to 1. To convert, divide by 255 (ff).
$r /= 255;
$g /= 255;
$b /= 255;
$myMax = max($r, $g, $b);
$myMin = min($r, $g, $b);
$maxAdd = ($myMax + $myMin);
$maxSub = ($myMax - $myMin);
//luminence is (max + min)/2
$h = 0;
$s = 0;
$l = ($maxAdd / 2.0);
//if all the numbers are equal, there is no saturation (greyscale).
if($myMin != $myMax){
if ($l < 0.5) {
$s = ($maxSub / $maxAdd);
} else {
$s = (2.0 - $myMax - $myMin); //note order of opperations - can't use $maxSub here
$s = ($maxSub / $s);
}
//find hue
switch($myMax){
case $r:
$h = ($g - $b);
$h = ($h / $maxSub);
break;
case $g:
$h = ($b - $r);
$h = ($h / $maxSub);
$h = ($h + 2.0);
break;
case $b:
$h = ($r - $g);
$h = ($h / $maxSub);
$h = ($h + 4.0);
break;
}
}
$hsl = hslToDegPercPerc($h, $s, $l);
return $hsl;
}
##HSL(0-1范围)到程度，百分比，百分比格式
对于数学计算，HSL在0-1范围内更容易处理，但对于人类可读性而言，在Degrees, Percent, Percent中更容易处理。该函数接受范围为0-1的HSL，并返回以度、百分比、百分比为单位的HSL。
/**
* Input: HSL in ranges 0-1.
* Output: HSL in format Deg, Perc, Perc.
*
* Note: rgbToHsl calls this function by default.
*
* Multiplies $h by 60, and $s and $l by 100.
*/
function hslToDegPercPerc($h, $s, $l) {
//convert h to degrees
$h *= 60;
if ($h < 0) {
$h += 360;
}
//convert s and l to percentage
$s *= 100;
$l *= 100;
$hsl['h'] = $h;
$hsl['s'] = $s;
$hsl['l'] = $l;
return $hsl;
}
##HSL(度，百分比，百分比格式)到范围为0-1的HSL
该函数将格式为Degrees, Percent, Percent的HSL转换为0-1的范围，以便于计算。
/**
* Input: HSL in format Deg, Perc, Perc
* Output: An array containing HSL in ranges 0-1
*
* Divides $h by 60, and $s and $l by 100.
*
* hslToRgb calls this by default.
*/
function degPercPercToHsl($h, $s, $l) {
//convert h, s, and l back to the 0-1 range
//convert the hue's 360 degrees in a circle to 1
$h /= 360;
//convert the saturation and lightness to the 0-1
//range by multiplying by 100
$s /= 100;
$l /= 100;
$hsl['h'] = $h;
$hsl['s'] = $s;
$hsl['l'] = $l;
return $hsl;
}
##HSL到RGB
输入:格式为度，百分比，百分比的HSL 输出:RGB，格式为255,255,255。
/**
* Converts an HSL color value to RGB. Conversion formula
* adapted from http://www.niwa.nu/2013/05/math-behind-colorspace-conversions-rgb-hsl/.
* Assumes h, s, and l are in the format Degrees,
* Percent, Percent, and returns r, g, and b in
* the range [0 - 255].
*
* Called by hslToHex by default.
*
* Calls:
* degPercPercToHsl
* hueToRgb
*
* @param Number h The hue value
* @param Number s The saturation level
* @param Number l The luminence
* @return Array The RGB representation
*/
function hslToRgb($h, $s, $l){
$hsl = degPercPercToHsl($h, $s, $l);
$h = $hsl['h'];
$s = $hsl['s'];
$l = $hsl['l'];
//If there's no saturation, the color is a greyscale,
//so all three RGB values can be set to the lightness.
//(Hue doesn't matter, because it's grey, not color)
if ($s == 0) {
$r = $l * 255;
$g = $l * 255;
$b = $l * 255;
}
else {
//calculate some temperary variables to make the
//calculation eaisier.
if ($l < 0.5) {
$temp2 = $l * (1 + $s);
} else {
$temp2 = ($l + $s) - ($s * $l);
}
$temp1 = 2 * $l - $temp2;
//run the calculated vars through hueToRgb to
//calculate the RGB value. Note that for the Red
//value, we add a third (120 degrees), to adjust
//the hue to the correct section of the circle for
//red. Simalarly, for blue, we subtract 1/3.
$r = 255 * hueToRgb($temp1, $temp2, $h + (1 / 3));
$g = 255 * hueToRgb($temp1, $temp2, $h);
$b = 255 * hueToRgb($temp1, $temp2, $h - (1 / 3));
}
$rgb['r'] = $r;
$rgb['g'] = $g;
$rgb['b'] = $b;
return $rgb;
}
###色调到RGB
hslToRgb调用此函数将色调转换为单独的RGB值。
/**
* Converts an HSL hue to it's RGB value.
*
* Input: $temp1 and $temp2 - temperary vars based on
* whether the lumanence is less than 0.5, and
* calculated using the saturation and luminence
* values.
* $hue - the hue (to be converted to an RGB
* value) For red, add 1/3 to the hue, green
* leave it alone, and blue you subtract 1/3
* from the hue.
*
* Output: One RGB value.
*
* Thanks to Easy RGB for this function (Hue_2_RGB).
* http://www.easyrgb.com/index.php?X=MATH&$h=19#text19
*
*/
function hueToRgb($temp1, $temp2, $hue) {
if ($hue < 0) {
$hue += 1;
}
if ($hue > 1) {
$hue -= 1;
}
if ((6 * $hue) < 1 ) {
return ($temp1 + ($temp2 - $temp1) * 6 * $hue);
} elseif ((2 * $hue) < 1 ) {
return $temp2;
} elseif ((3 * $hue) < 2 ) {
return ($temp1 + ($temp2 - $temp1) * ((2 / 3) - $hue) * 6);
}
return $temp1;
}
##HSL到Hex
输入:HSL格式的度，百分比，百分比 输出:十六进制格式00ff22(没有磅号)。
转换为RGB，然后分别转换为十六进制。
/**
* Converts HSL to Hex by converting it to
* RGB, then converting that to hex.
*
* string hslToHex($h, $s, $l[, $prependPound = true]
*
* $h is the Degrees value of the Hue
* $s is the Percentage value of the Saturation
* $l is the Percentage value of the Lightness
* $prependPound is a bool, whether you want a pound
* sign prepended. (optional - default=true)
*
* Calls:
* hslToRgb
*
* Output: Hex in the format: #00ff88 (with
* pound sign). Rounded to the nearest whole
* number.
*/
function hslToHex($h, $s, $l, $prependPound = true) {
//convert hsl to rgb
$rgb = hslToRgb($h,$s,$l);
//convert rgb to hex
$hexR = $rgb['r'];
$hexG = $rgb['g'];
$hexB = $rgb['b'];
//round to the nearest whole number
$hexR = round($hexR);
$hexG = round($hexG);
$hexB = round($hexB);
//convert to hex
$hexR = dechex($hexR);
$hexG = dechex($hexG);
$hexB = dechex($hexB);
//check for a non-two string length
//if it's 1, we can just prepend a
//0, but if it is anything else non-2,
//it must return false, as we don't
//know what format it is in.
if (strlen($hexR) != 2) {
if (strlen($hexR) == 1) {
//probably in format #0f4, etc.
$hexR = "0" . $hexR;
} else {
//unknown format
return false;
}
}
if (strlen($hexG) != 2) {
if (strlen($hexG) == 1) {
$hexG = "0" . $hexG;
} else {
return false;
}
}
if (strlen($hexB) != 2) {
if (strlen($hexB) == 1) {
$hexB = "0" . $hexB;
} else {
return false;
}
}
//if prependPound is set, will prepend a
//# sign to the beginning of the hex code.
//(default = true)
$hex = "";
if ($prependPound) {
$hex = "#";
}
$hex = $hex . $hexR . $hexG . $hexB;
return $hex;
}
