“距离"PHP中的颜色之间 [英] "Distance" between colours in PHP

问题描述

我正在寻找一种可以将两种颜色之间的距离准确地表示为数字或其他东西的函数.

I'm looking for a function that can accurately represent the distance between two colours as a number or something.

例如，我希望有一个十六进制值或 RGB 数组的数组，并且我想在给定颜色的数组中找到最相似的颜色

For example I am looking to have an array of HEX values or RGB arrays and I want to find the most similar colour in the array for a given colour

例如.我向函数传递一个 RGB 值，并返回数组中最接近"的颜色

eg. I pass a function a RGB value and the 'closest' colour in the array is returned

推荐答案

每种颜色在 HEX 代码中都表示为一个元组.要确定接近匹配，您需要分别减去每个 RGB 分量.

Each color is represented as a tuple in the HEX code. To determine close matches you need to subtract each RGB component separately.

示例:

Color 1: #112233 
Color 2: #122334
Color 3: #000000

Difference between color1 and color2: R=1,  G=1   B=1  = 0x3 
Difference between color3 and color1: R=11, G=22, B=33 = 0x66

So color 1 and color 2 are closer than
1 and 3.

编辑

所以你想要最接近的命名颜色?使用每种颜色的十六进制值创建一个数组，迭代它并返回名称.像这样;

So you want the closest named color? Create an array with the hex values of each color, iterate it and return the name. Something like this;

function getColor($rgb)
{
    // these are not the actual rgb values
    $colors = array(BLUE =>0xFFEEBB, RED => 0x103ABD, GREEN => 0x123456);

    $largestDiff = 0;
    $closestColor = "";
    foreach ($colors as $name => $rgbColor)
    {
        if (colorDiff($rgbColor,$rgb) > $largestDiff)
        {
            $largestDiff = colorDiff($rgbColor,$rgb);
            $closestColor = $name;
        }

    }
    return $closestColor;

}

function colorDiff($rgb1,$rgb2)
{
    // do the math on each tuple
    // could use bitwise operates more efficiently but just do strings for now.
    $red1   = hexdec(substr($rgb1,0,2));
    $green1 = hexdec(substr($rgb1,2,2));
    $blue1  = hexdec(substr($rgb1,4,2));

    $red2   = hexdec(substr($rgb2,0,2));
    $green2 = hexdec(substr($rgb2,2,2));
    $blue2  = hexdec(substr($rgb2,4,2));

    return abs($red1 - $red2) + abs($green1 - $green2) + abs($blue1 - $blue2) ;

}

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