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
找到了最简单的方法,蟒蛇来拯救:D
colorsys。Hls_to_rgb (h, l, s) 将颜色从HLS坐标转换为RGB坐标。
其他回答
@Mohsen代码的PHP实现(包括Test!)
很抱歉重新发布这篇文章。但我真的没有看到任何其他实现可以提供我所需的质量。
/**
* 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 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 $p;
}
function hslToRgb($h, $s, $l){
if($s == 0){
$r = $l;
$g = $l;
$b = $l; // achromatic
}else{
$q = $l < 0.5 ? $l * (1 + $s) : $l + $s - $l * $s;
$p = 2 * $l - $q;
$r = hue2rgb($p, $q, $h + 1/3);
$g = hue2rgb($p, $q, $h);
$b = hue2rgb($p, $q, $h - 1/3);
}
return array(round($r * 255), round($g * 255), round($b * 255));
}
/* Uncomment to test * /
for ($i=0;$i<360;$i++) {
$rgb=hslToRgb($i/360, 1, .9);
echo '<div style="background-color:rgb(' .$rgb[0] . ', ' . $rgb[1] . ', ' . $rgb[2] . ');padding:2px;"></div>';
}
/* End Test */
Unity3D c#代码来自Mohsen的回答。
以下是Mohsen用c#编写的针对Unity3D的回答。它改编自上面Alec Thilenius给出的c#答案。
using UnityEngine;
using System.Collections;
public class ColorTools {
/// <summary>
/// Converts an HSL color value to RGB.
/// Input: Vector4 ( X: [0.0, 1.0], Y: [0.0, 1.0], Z: [0.0, 1.0], W: [0.0, 1.0] )**strong text**
/// Output: Color ( R: [0.0, 1.0], G: [0.0, 1.0], B: [0.0, 1.0], A: [0.0, 1.0] )
/// </summary>
/// <param name="hsl">Vector4 defining X = h, Y = s, Z = l, W = a. Ranges [0, 1.0]</param>
/// <returns>RGBA Color. Ranges [0.0, 1.0]</returns>
public static Color HslToRgba(Vector4 hsl)
{
float r, g, b;
if (hsl.y == 0.0f)
r = g = b = hsl.z;
else
{
var q = hsl.z < 0.5f ? hsl.z * (1.0f + hsl.y) : hsl.z + hsl.y - hsl.z * hsl.y;
var p = 2.0f * hsl.z - q;
r = HueToRgb(p, q, hsl.x + 1.0f / 3.0f);
g = HueToRgb(p, q, hsl.x);
b = HueToRgb(p, q, hsl.x - 1.0f / 3.0f);
}
return new Color(r, g, b, hsl.w);
}
// Helper for HslToRgba
private static float HueToRgb(float p, float q, float t)
{
if (t < 0.0f) t += 1.0f;
if (t > 1.0f) t -= 1.0f;
if (t < 1.0f / 6.0f) return p + (q - p) * 6.0f * t;
if (t < 1.0f / 2.0f) return q;
if (t < 2.0f / 3.0f) return p + (q - p) * (2.0f / 3.0f - t) * 6.0f;
return p;
}
/// <summary>
/// Converts an RGB color value to HSL.
/// Input: Color ( R: [0.0, 1.0], G: [0.0, 1.0], B: [0.0, 1.0], A: [0.0, 1.0] )
/// Output: Vector4 ( X: [0.0, 1.0], Y: [0.0, 1.0], Z: [0.0, 1.0], W: [0.0, 1.0] )
/// </summary>
/// <param name="rgba"></param>
/// <returns></returns>
public static Vector4 RgbaToHsl(Color rgba)
{
float max = (rgba.r > rgba.g && rgba.r > rgba.b) ? rgba.r :
(rgba.g > rgba.b) ? rgba.g : rgba.b;
float min = (rgba.r < rgba.g && rgba.r < rgba.b) ? rgba.r :
(rgba.g < rgba.b) ? rgba.g : rgba.b;
float h, s, l;
h = s = 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 (rgba.r > rgba.g && rgba.r > rgba.b)
h = (rgba.g - rgba.b) / d + (rgba.g < rgba.b ? 6.0f : 0.0f);
else if (rgba.g > rgba.b)
h = (rgba.b - rgba.r) / d + 2.0f;
else
h = (rgba.r - rgba.g) / d + 4.0f;
h /= 6.0f;
}
return new Vector4(h, s, l, rgba.a);
}
}
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;
}
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));
c++实现,性能可能比@Mohsen代码更好。它使用[0-6]范围的色调,避免除和乘6。S和L的范围为[0,1]
void fromRGBtoHSL(float rgb[], float hsl[])
{
const float maxRGB = max(rgb[0], max(rgb[1], rgb[2]));
const float minRGB = min(rgb[0], min(rgb[1], rgb[2]));
const float delta2 = maxRGB + minRGB;
hsl[2] = delta2 * 0.5f;
const float delta = maxRGB - minRGB;
if (delta < FLT_MIN)
hsl[0] = hsl[1] = 0.0f;
else
{
hsl[1] = delta / (hsl[2] > 0.5f ? 2.0f - delta2 : delta2);
if (rgb[0] >= maxRGB)
{
hsl[0] = (rgb[1] - rgb[2]) / delta;
if (hsl[0] < 0.0f)
hsl[0] += 6.0f;
}
else if (rgb[1] >= maxRGB)
hsl[0] = 2.0f + (rgb[2] - rgb[0]) / delta;
else
hsl[0] = 4.0f + (rgb[0] - rgb[1]) / delta;
}
}
void fromHSLtoRGB(const float hsl[], float rgb[])
{
if(hsl[1] < FLT_MIN)
rgb[0] = rgb[1] = rgb[2] = hsl[2];
else if(hsl[2] < FLT_MIN)
rgb[0] = rgb[1] = rgb[2] = 0.0f;
else
{
const float q = hsl[2] < 0.5f ? hsl[2] * (1.0f + hsl[1]) : hsl[2] + hsl[1] - hsl[2] * hsl[1];
const float p = 2.0f * hsl[2] - q;
float t[] = {hsl[0] + 2.0f, hsl[0], hsl[0] - 2.0f};
for(int i=0; i<3; ++i)
{
if(t[i] < 0.0f)
t[i] += 6.0f;
else if(t[i] > 6.0f)
t[i] -= 6.0f;
if(t[i] < 1.0f)
rgb[i] = p + (q - p) * t[i];
else if(t[i] < 3.0f)
rgb[i] = q;
else if(t[i] < 4.0f)
rgb[i] = p + (q - p) * (4.0f - t[i]);
else
rgb[i] = p;
}
}
}