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。
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
对于所有说Garry Tan解决方案转换不正确从RGB到HSL和回来。这是因为他在代码中遗漏了数字的一部分。 我纠正了他的代码(javascript)。 对不起,俄语的链接,但在英语缺席- HSL-wiki
function toHsl(r, g, b)
{
r /= 255.0;
g /= 255.0;
b /= 255.0;
var max = Math.max(r, g, b);
var min = Math.min(r, g, b);
var h, s, l = (max + min) / 2.0;
if(max == min)
{
h = s = 0;
}
else
{
var d = max - min;
s = (l > 0.5 ? d / (2.0 - max - min) : d / (max + min));
if(max == r && g >= b)
{
h = 1.0472 * (g - b) / d ;
}
else if(max == r && g < b)
{
h = 1.0472 * (g - b) / d + 6.2832;
}
else if(max == g)
{
h = 1.0472 * (b - r) / d + 2.0944;
}
else if(max == b)
{
h = 1.0472 * (r - g) / d + 4.1888;
}
}
return {
str: 'hsl(' + parseInt(h / 6.2832 * 360.0 + 0.5) + ',' + parseInt(s * 100.0 + 0.5) + '%,' + parseInt(l * 100.0 + 0.5) + '%)',
obj: { h: parseInt(h / 6.2832 * 360.0 + 0.5), s: parseInt(s * 100.0 + 0.5), l: parseInt(l * 100.0 + 0.5) }
};
};
其他回答
维基百科上关于HSL和HSV的文章包含了一些公式。计算有点棘手,所以看一下现有的实现可能会有用。
Garry Tan在他的博客上发布了一个Javascript解决方案(他把它归为现已不存在的mjijackson.com,但存档在这里,原作者有一个要点——感谢user2441511)。
代码重新发布如下:
HSL到RGB:
/**
* Converts an HSL color value to RGB. Conversion formula
* adapted from http://en.wikipedia.org/wiki/HSL_color_space.
* Assumes h, s, and l are contained in the set [0, 1] and
* returns r, g, and b in the set [0, 255].
*
* @param {number} h The hue
* @param {number} s The saturation
* @param {number} l The lightness
* @return {Array} The RGB representation
*/
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:
/**
* Converts an RGB color value to HSL. Conversion formula
* adapted from http://en.wikipedia.org/wiki/HSL_color_space.
* Assumes r, g, and b are contained in the set [0, 255] and
* returns h, s, and l in the set [0, 1].
*
* @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){
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];
}
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);
}
Mohsen代码的Java实现
注意,所有整数都声明为浮点数(即1f),必须是浮点数,否则您将选择灰色。
HSL到RGB
/**
* Converts an HSL color value to RGB. Conversion formula
* adapted from http://en.wikipedia.org/wiki/HSL_color_space.
* Assumes h, s, and l are contained in the set [0, 1] and
* returns r, g, and b in the set [0, 255].
*
* @param h The hue
* @param s The saturation
* @param l The lightness
* @return int array, the RGB representation
*/
public static int[] hslToRgb(float h, float s, float l){
float r, g, b;
if (s == 0f) {
r = g = b = l; // achromatic
} else {
float q = l < 0.5f ? l * (1 + s) : l + s - l * s;
float p = 2 * l - q;
r = hueToRgb(p, q, h + 1f/3f);
g = hueToRgb(p, q, h);
b = hueToRgb(p, q, h - 1f/3f);
}
int[] rgb = {to255(r), to255(g), to255(b)};
return rgb;
}
public static int to255(float v) { return (int)Math.min(255,256*v); }
/** Helper method that converts hue to rgb */
public static float hueToRgb(float p, float q, float t) {
if (t < 0f)
t += 1f;
if (t > 1f)
t -= 1f;
if (t < 1f/6f)
return p + (q - p) * 6f * t;
if (t < 1f/2f)
return q;
if (t < 2f/3f)
return p + (q - p) * (2f/3f - t) * 6f;
return p;
}
RGB到HSL
/**
* Converts an RGB color value to HSL. Conversion formula
* adapted from http://en.wikipedia.org/wiki/HSL_color_space.
* Assumes pR, pG, and bpBare contained in the set [0, 255] and
* returns h, s, and l in the set [0, 1].
*
* @param pR The red color value
* @param pG The green color value
* @param pB The blue color value
* @return float array, the HSL representation
*/
public static float[] rgbToHsl(int pR, int pG, int pB) {
float r = pR / 255f;
float g = pG / 255f;
float b = pB / 255f;
float max = (r > g && r > b) ? r : (g > b) ? g : b;
float min = (r < g && r < b) ? r : (g < b) ? g : b;
float h, s, l;
l = (max + min) / 2.0f;
if (max == min) {
h = s = 0.0f;
} else {
float d = max - min;
s = (l > 0.5f) ? d / (2.0f - max - min) : d / (max + min);
if (r > g && r > b)
h = (g - b) / d + (g < b ? 6.0f : 0.0f);
else if (g > b)
h = (b - r) / d + 2.0f;
else
h = (r - g) / d + 4.0f;
h /= 6.0f;
}
float[] hsl = {h, s, l};
return hsl;
}
简短而精确- JS
使用这个JS代码(更多:rgb2hsl, hsv2rgb rgb2hsv和hsl2hsv) - php版本在这里
// input: h as an angle in [0,360] and s,l in [0,1] - output: r,g,b in [0,1]
function hsl2rgb(h,s,l)
{
let a=s*Math.min(l,1-l);
let f= (n,k=(n+h/30)%12) => l - a*Math.max(Math.min(k-3,9-k,1),-1);
return [f(0),f(8),f(4)];
}
// oneliner version let hsl2rgb = (h,s,l, a=s*Math.min(l,1-l), f= (n,k=(n+h/30)%12) => l - a*Math.max(Math.min(k-3,9-k,1),-1)) => [f(0),f(8),f(4)]; // r,g,b are in [0-1], result e.g. #0812fa. let rgb2hex = (r,g,b) => "#" + [r,g,b].map(x=>Math.round(x*255).toString(16).padStart(2,0) ).join(''); console.log(`hsl: (30,0.2,0.3) --> rgb: (${hsl2rgb(30,0.2,0.3)}) --> hex: ${rgb2hex(...hsl2rgb(30,0.2,0.3))}`); // --------------- // UX // --------------- rgb= [0,0,0]; hs= [0,0,0]; let $ = x => document.querySelector(x); function changeRGB(i,e) { rgb[i]=e.target.value/255; hs = rgb2hsl(...rgb); refresh(); } function changeHS(i,e) { hs[i]=e.target.value/(i?255:1); rgb= hsl2rgb(...hs); refresh(); } function refresh() { rr = rgb.map(x=>x*255|0).join(', ') hh = rgb2hex(...rgb); tr = `RGB: ${rr}` th = `HSL: ${hs.map((x,i)=>i? (x*100).toFixed(2)+'%':x|0).join(', ')}` thh= `HEX: ${hh}` $('.box').style.backgroundColor=`rgb(${rr})`; $('.infoRGB').innerHTML=`${tr}`; $('.infoHS').innerHTML =`${th}\n${thh}`; $('#r').value=rgb[0]*255; $('#g').value=rgb[1]*255; $('#b').value=rgb[2]*255; $('#h').value=hs[0]; $('#s').value=hs[1]*255; $('#l').value=hs[2]*255; } function rgb2hsl(r,g,b) { let a=Math.max(r,g,b), n=a-Math.min(r,g,b), f=(1-Math.abs(a+a-n-1)); let h= n && ((a==r) ? (g-b)/n : ((a==g) ? 2+(b-r)/n : 4+(r-g)/n)); return [60*(h<0?h+6:h), f ? n/f : 0, (a+a-n)/2]; } refresh(); .box { width: 50px; height: 50px; margin: 20px; } body { display: flex; } <div> <input id="r" type="range" min="0" max="255" oninput="changeRGB(0,event)">R<br> <input id="g" type="range" min="0" max="255" oninput="changeRGB(1,event)">G<br> <input id="b" type="range" min="0" max="255" oninput="changeRGB(2,event)">B<br> <pre class="infoRGB"></pre> </div> <div> <div class="box hsl"></div> </div> <div> <input id="h" type="range" min="0" max="360" oninput="changeHS(0,event)">H<br> <input id="s" type="range" min="0" max="255" oninput="changeHS(1,event)">S<br> <input id="l" type="range" min="0" max="255" oninput="changeHS(2,event)">L<br> <pre class="infoHS"></pre><br> </div>
以下是我在wiki +错误分析中发现并精确描述的公式,