在 javascript 中平均 2 个十六进制颜色在一起

Question

好吧，我想我会把这个扔出去让大家思考一下。

给定一个 函数 （用 javascript 编写），它需要两个格式化为十六进制颜色的字符串（ex #FF0000）

返回十六进制颜色，它是传递的两种颜色的平均值。

function averageColors(firstColor,secondColor)
{
  ...
  return avgColor;
}

--编辑--

平均值定义为

如果传递的颜色是黄色，第二个颜色是浅紫色，则返回的颜色将是中橙色

Answer 1

新答案（2024）

使用浏览器内置的

color-mix

CSS 属性，我们希望能够更灵活可靠地做到这一点：

export const mixColors = (
  colorA: string,
  colorB: string,
  mix = 0.5,
  space = "hsl",
) => {
  const style = `color-mix(in ${space}, ${colorA}, ${colorB} ${100 * mix}%)`;
  const div = document.createElement("div");
  if (!window.matchMedia(`@supports (color: ${style}`)) return colorA;
  div.style.color = style;
  document.body.append(div);
  const [r = 0, g = 0, b = 0] = window
    .getComputedStyle(div)
    .color.split(/\s/)
    .map(parseFloat)
    .filter((value) => !Number.isNaN(value));
  div.remove();
  const floatToHex = (value: number) =>
    Math.round(255 * value)
      .toString(16)
      .padStart(2, "0");
  return "#" + [r, g, b].map(floatToHex).join("");
};

现在我们可以做任何颜色空间，而不仅仅是我的旧答案所做的 RGB。我们可以做命名颜色，如

maroon

或任何其他有效的 CSS 颜色。

这还会检查

color-mix

支持，并回退到仅返回第一种颜色。

注意：这是基于我在 Chrome/Firefox/Safari 中的测试，我观察到

getComputedStyle

会计算，例如，

color-mix(in hsl, red, orange 10%)

值可小至

color(srgb 1 0.0647058 0)

形式。我已经找到了这两个资源，但我有点不清楚是否存在边缘情况，它不会采用这种格式：

getComputedStyle 规范中是否指定了颜色格式？ https://github.com/w3c/csswg-drafts/issues/7302

---

旧答案

一种按指定百分比混合两种十六进制颜色的快速/肮脏/方便/ES6 方法：

// blend two hex colors together by an amount
function blendColors(colorA, colorB, amount) {
  const [rA, gA, bA] = colorA.match(/\w\w/g).map((c) => parseInt(c, 16));
  const [rB, gB, bB] = colorB.match(/\w\w/g).map((c) => parseInt(c, 16));
  const r = Math.round(rA + (rB - rA) * amount).toString(16).padStart(2, '0');
  const g = Math.round(gA + (gB - gA) * amount).toString(16).padStart(2, '0');
  const b = Math.round(bA + (bB - bA) * amount).toString(16).padStart(2, '0');
  return '#' + r + g + b;
}

console.log(blendColors('#00FF66', '#443456', 0.5));

其中

amount

应该是

0

到

1

，其中

0

恰好是

colorA

，

1

恰好是

colorB

，

0.5

是“中点”。

Answer 2

我讨厌听起来像破烂的 jQuery 记录，但是is已经有一个jQuery 插件了。

Answer 3

如果你不想打扰很多不必要的东西，只需要几行 POJS：

// Expects input as 'nnnnnn' where each nn is a 
// 2 character hex number for an RGB color value
// e.g. #3f33c6
// Returns the average as a hex number without leading #
var averageRGB = (function () {

  // Keep helper stuff in closures
  var reSegment = /[\da-z]{2}/gi;

  // If speed matters, put these in for loop below
  function dec2hex(v) {return v.toString(16);}
  function hex2dec(v) {return parseInt(v,16);}

  return function (c1, c2) {

    // Split into parts
    var b1 = c1.match(reSegment);
    var b2 = c2.match(reSegment);
    var t, c = [];

    // Average each set of hex numbers going via dec
    // always rounds down
    for (var i=b1.length; i;) {
      t = dec2hex( (hex2dec(b1[--i]) + hex2dec(b2[i])) >> 1 );

      // Add leading zero if only one character
      c[i] = t.length == 2? '' + t : '0' + t; 
    }
    return  c.join('');
  }
}());

Answer 4

对我来说就像是家庭作业，但这是我的线索。

取 R、G 和 B 的每个十六进制值，并对它们进行平均。 如有必要，请转换为十进制进行数学计算。

函数 d2h(d) {return d.toString(16).padStart(2,'0');}

函数 h2d(h) {返回 parseInt(h,16);}

然后返回一个包含三个元素的串联值的字符串。

Answer 5

这是一组紧凑的相关（相互依赖）函数：

十六进制⟷RGB颜色转换：

function hexToRgb(h){return['0x'+h[1]+h[2]|0,'0x'+h[3]+h[4]|0,'0x'+h[5]+h[6]|0]}
function rgbToHex(r,g,b){return"#"+((1<<24)+(r<<16)+(g<<8)+ b).toString(16).slice(1);}

计算 2 个十六进制颜色的平均值：^{_{需要转换函数（上文）}}

function avgHex(h1,h2){a=hexToRgb(h1);b=hexToRgb(h2); return rgbToHex(~~((a[0]+b[0])/2),~~((a[1]+b[1])/2),~~((a[2]+b[2])/2));}

生成随机十六进制颜色：

function rndHex(){return'#'+('00000'+(Math.random()*(1<<24)|0).toString(16)).slice(-6);}

_{运行演示片段：}

// color functions (average/random/conversion)
function hexToRgb(h){return['0x'+h[1]+h[2]|0,'0x'+h[3]+h[4]|0,'0x'+h[5]+h[6]|0]}
function rgbToHex(r,g,b){return"#"+((1<<24)+(r<<16)+(g<<8)+ b).toString(16).slice(1);}
function rndHex(){return'#'+('00000'+(Math.random()*(1<<24)|0).toString(16)).slice(-6);}
function avgHex(h1,h2){a=hexToRgb(h1);b=hexToRgb(h2);return rgbToHex(~~((a[0]+b[0])/2),~~((a[1]+b[1])/2),~~((a[2]+b[2])/2));}

//code below is just for the demo
function auto(){if(chk.checked){tmr=setInterval(rnd,1000)}else{clearTimeout(tmr)}}auto();
function rnd(go){for(h of[h1,h2]){h.value=rndHex();}avgInput();}
addEventListener('input',avgInput); 
function avgInput(){ // get avg & colorize
 ha.value=avgHex(h1.value,h2.value);
 for(h of [h1,h2,ha])h.style.background=h.value;
}

*{font-family:monospace;font-size:5vw; }

<label>Color 1 → <input id='h1'></label><br>
<label>Average → <input id='ha'></label><br>
<label>Color 2 → <input id='h2'></label><br>
<label>Type hex colors or <input type='checkbox' id='chk' onclick='auto()' style=' transform: scale(1.5)'checked>Autorandom</label>

Answer 6

这是我的功能，希望对你有帮助。

function averageColors( colorArray ){
    var red = 0, green = 0, blue = 0;

    for ( var i = 0; i < colorArray.length; i++ ){
        red += hexToR( "" + colorArray[ i ] + "" );
        green += hexToG( "" + colorArray[ i ] + "" );
        blue += hexToB( "" + colorArray[ i ] + "" );
    }

    //Average RGB
    red = (red/colorArray.length);
    green = (green/colorArray.length);
    blue = (blue/colorArray.length);

    console.log(red + ", " + green + ", " + blue);
    return new THREE.Color( "rgb("+ red +","+ green +","+ blue +")" );
}

//get the red of RGB from a hex value
function hexToR(h) {return parseInt((cutHex( h )).substring( 0, 2 ), 16 )}

//get the green of RGB from a hex value
function hexToG(h) {return parseInt((cutHex( h )).substring( 2, 4 ), 16 )}

//get the blue of RGB from a hex value
function hexToB(h) {return parseInt((cutHex( h )).substring( 4, 6 ), 16 )}

//cut the hex into pieces
function cutHex(h) {if(h.charAt(1) == "x"){return h.substring( 2, 8 );} else {return h.substring(1,7);}}

Answer 7

参加这个聚会已经很晚了，但我个人正在寻找一种方法来平均未定义数量的十六进制值。根据答案@RobG，我想出了这个。当然，您添加的颜色越多，它们就会变得越棕色/灰色，但是，也许这会有所帮助！

/**
 * Averages an array of hex colors. Returns one hex value (with leading #)
 *
 * @param {Array} colors - An array of hex strings, e.g. ["#001122", "#001133", ...]
 */
function averageHex(colors) {

  // transform all hex codes to integer arrays, e.g. [[R, G, B], [R,G,B], ...]
  let numbers = colors.map(function(hex) {
    // split in seperate R, G and B
    let split = hex.match(/[\da-z]{2}/gi);

    // transform to integer values
    return split.map(function(toInt) {
      return parseInt(toInt, 16);
    });
  });

  // reduce the array by averaging all values, resulting in an average [R, G, B]
  let averages = numbers.reduce(function(total, amount, index, array) {
    return total.map(function(subtotal, subindex) {

      // if we reached the last color, average it out and return the hex value
      if (index == array.length - 1) {

        let result = Math.round((subtotal + amount[subindex]) / array.length).toString(16);

        // add a leading 0 if it is only one character
        return result.length == 2 ? '' + result : '0' + result;

      } else {
        return subtotal + amount[subindex];
      }
    });
  });

  // return them as a single hex string
  return "#" + averages.join('');
}

console.log(averageHex(["#FF110C", "#0000AA", "#55063d", "#06551e"]));
// expected: #571b44, see also https://www.colorhexa.com/ and enter "#FF110C+#0000AA+#55063d+#06551e"

Answer 8

这是函数

function avgColor(color1, color2) {
  //separate each color alone (red, green, blue) from the first parameter (color1) 
  //then convert to decimal
  let color1Decimal = {
    red: parseInt(color1.slice(0, 2), 16),
    green: parseInt(color1.slice(2, 4), 16),
    blue: parseInt(color1.slice(4, 6), 16)
  }
  //separate each color alone (red, green, blue) from the second parameter (color2) 
  //then convert to decimal
  let color2Decimal = {
    red: parseInt(color2.slice(0, 2), 16),
    green: parseInt(color2.slice(2, 4), 16),
    blue: parseInt(color2.slice(4, 6), 16),
  }
  // calculate the average of each color (red, green, blue) from each parameter (color1,color2) 
  let color3Decimal = {
    red: Math.ceil((color1Decimal.red + color2Decimal.red) / 2),
    green: Math.ceil((color1Decimal.green + color2Decimal.green) / 2),
    blue: Math.ceil((color1Decimal.blue + color2Decimal.blue) / 2)
  }
  //convert the result to hexadecimal and don't forget if the result is one character
  //then convert it to uppercase
  let color3Hex = {
    red: color3Decimal.red.toString(16).padStart(2, '0').toUpperCase(),
    green: color3Decimal.green.toString(16).padStart(2, '0').toUpperCase(),
    blue: color3Decimal.blue.toString(16).padStart(2, '0').toUpperCase()
  }
  //put the colors (red, green, blue) together to have the output
  let color3 = color3Hex.red + color3Hex.green + color3Hex.blue
  return color3
}
console.log(avgColor("FF33CC", "3300FF"))
// avgColor("FF33CC", "3300FF") => "991AE6"

console.log(avgColor("991AE6", "FF0000"))
// avgColor("991AE6", "FF0000") => "CC0D73"

console.log(avgColor("CC0D73", "0000FF"))
// avgColor("CC0D73", "0000FF") => "6607B9"

要检查，您可以使用此链接和中点 1，然后混合 https://meyerweb.com/eric/tools/color-blend/#CC0D73:0000FF:1:hex