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Javascript - Sorting rgb values

Using javascript / jquery, I want to sort an array of rgba values ​​for the colors of the visible spectrum. By doing this, how shades should be grouped together. Is there a plugin to do this or how can I do this?

Spectrum Image: http://www.gamonline.com/catalog/colortheory/images/spectrum.gif

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3 answers

If your color array looks like this:

var rgbArr = [c1, c2, c3, ...]

where each color ciis an array of three numbers between 0 and 255

ci = [red, green, blue]

then you can use this function to convert colors to HSL

function rgbToHsl(c) {
  var r = c[0]/255, g = c[1]/255, b = c[2]/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 new Array(h * 360, s * 100, l * 100);
}

and sort them by color

var sortedRgbArr = rgbArr.map(function(c, i) {
  // Convert to HSL and keep track of original indices
  return {color: rgbToHsl(c), index: i};
}).sort(function(c1, c2) {
  // Sort by hue
  return c1.color[0] - c2.color[0];
}).map(function(data) {
  // Retrieve original RGB color
  return rgbArr[data.index];
});

Here is a running example (thanks to Ionică Bizău ):

function display(container, arr) {
  container = document.querySelector(container);
  arr.forEach(function(c) {
    var el = document.createElement("div");
    el.style.backgroundColor = "rgb(" + c.join(", ") + ")";
    container.appendChild(el);
  })
}
function rgbToHsl(c) {
  var r = c[0] / 255,
      g = c[1] / 255,
      b = c[2] / 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 new Array(h * 360, s * 100, l * 100);
}

var rgbArr = [];
for (var i = 0; i < 100; ++i) {
  rgbArr.push([
    Math.floor(Math.random() * 256),
    Math.floor(Math.random() * 256),
    Math.floor(Math.random() * 256)
  ]);
}
display("#before", rgbArr);

var sortedRgbArr = rgbArr.map(function(c, i) {
  // Convert to HSL and keep track of original indices
  return {color: rgbToHsl(c), index: i};
}).sort(function(c1, c2) {
  // Sort by hue
  return c1.color[0] - c2.color[0];
}).map(function(data) {
  // Retrieve original RGB color
  return rgbArr[data.index];
});
display("#after", sortedRgbArr);
#before > div,
#after > div {
  width: 1%;
  height: 20px;
  display: inline-block;
}
Random colors: <div id="before"></div>
Same colors, sorted by hue: <div id="after"></div>
Run codeHide result

sortedRgbArr rgb rgbArr, , .

, HSL :

HSL spectrum

, , .

, , , . rgb, , .

, , , . HSL.

c1.color[0] - c2.color[0] c2.color[0] - c1.color[0], , .

+6

. , .

, ​​ Oriol. sc-color library:

var sorted = colorArray.sort(function(colorA, colorB) {
    return sc_color(colorA).hue() - sc_color(colorB).hue();
});
+14

Another example.

Sort RGB with HUE

Original from

http://www.runtime-era.com/2011/11/grouping-html-hex-colors-by-hue-in.html

Fiddle http://jsfiddle.net/bg17sa9b/

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