HSL to RGB

2024-01-05 19:58

文章标签 rgb hsl

本文主要是介绍HSL to RGB，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

转载:http://axonflux.com/handy-rgb-to-hsl-and-rgb-to-hsv-color-model-c

Reposted from mjijackson.com -- this is so cool that we should make sure there are more copies of this on the net, just in case. =D

Here is a set of additive color model conversion algorithms that I found published on Wikipedia and have implemented in JavaScript. It was surprisingly difficult to find these actually implemented anywhere in compact, efficient, and bug-free code, so I wrote my own. These should be easily portable to other programming languages if desired.

/*** 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];
}/*** 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{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 [r * 255, g * 255, b * 255];
}/*** Converts an RGB color value to HSV. Conversion formula* adapted from http://en.wikipedia.org/wiki/HSV_color_space.* Assumes r, g, and b are contained in the set [0, 255] and* returns h, s, and v 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 HSV representation*/
function rgbToHsv(r, g, b){r = r/255, g = g/255, b = b/255;var max = Math.max(r, g, b), min = Math.min(r, g, b);var h, s, v = max;var d = max - min;s = max == 0 ? 0 : d / max;if(max == min){h = 0; // achromatic}else{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, v];
}/*** Converts an HSV color value to RGB. Conversion formula* adapted from http://en.wikipedia.org/wiki/HSV_color_space.* Assumes h, s, and v 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  v       The value* @return  Array           The RGB representation*/
function hsvToRgb(h, s, v){var r, g, b;var i = Math.floor(h * 6);var f = h * 6 - i;var p = v * (1 - s);var q = v * (1 - f * s);var t = v * (1 - (1 - f) * s);switch(i % 6){case 0: r = v, g = t, b = p; break;case 1: r = q, g = v, b = p; break;case 2: r = p, g = v, b = t; break;case 3: r = p, g = q, b = v; break;case 4: r = t, g = p, b = v; break;case 5: r = v, g = p, b = q; break;}return [r * 255, g * 255, b * 255];
}