get image color palette

image.php

<?php
namespace Sonsuzdongu;

class Image
{
    private $colors = array(
            "black"         => array(0, 0, 0),
            "green"         => array(0, 128, 0),
            "green:x"       => array(120, 150, 70),
            "green:xxx"     => array(0, 255, 0),
            "silver"        => array(192, 192, 192),
            "gray"          => array(128, 0, 128),
            "gray:x"        => array(160, 160, 160),
            "gray:xx"       => array(110, 120, 120),
            "white"         => array(255, 255, 255),
            "yellow"        => array(255, 255, 0),
            "yellow:xxx"    => array(128, 128, 0),
            "red"           => array(255, 30, 30),
            "red:x"         => array(215, 90, 110),
            "red:xx"        => array(128, 0, 0),
            "brown"         => array(200, 150, 80),
            "brown:x"       => array(200, 190, 180),
            "orange"        => array(230, 120, 50),
            "blue"          => array(0, 0, 255),
            "blue:x"        => array(70, 190, 190),
            "blue:xx"       => array(0, 255, 255),
            "blue:xxx"      => array(0, 128, 128),
            "blue:xxxx"     => array(0, 0, 128),
            "purple"        => array(128, 0, 128),
            "purple:xx"     => array(255, 0, 255),
        );

    private function distancel2(array $color1, array $color2)
    {
        return sqrt(pow($color1[0] - $color2[0], 2) +
            pow($color1[1] - $color2[1], 2) +
            pow($color1[2] - $color2[2], 2));
    }

    private function getClosest($val)
    {
        $distances = array();
        if (!is_array($val)) {
            return "";
        }
        foreach ($this->colors as $name => $c) {
            $distances[$name] = $this->distancel2($c, $val);
        }

        $mincolor = "";
        $minval = pow(2, 30); /*big value*/
        foreach ($distances as $k => $v) {
            if ($v < $minval) {
                $minval = $v;
                $mincolor = $k;
            }
        }

        return current(explode(":", $mincolor));
    }

    public function getImageColors($img)
    {
        $img = \ImageCreateFromJpeg($img);
        $imgw = imagesx($img);
        $imgh = imagesy($img);

        $im = imagecreatetruecolor(150, 150);
        imagecopyresized($im, $img, 0, 0, 0, 0, 150, 150, $imgw, $imgh);
        $imgw = imagesx($im);
        $imgh = imagesy($im);

        $n = $imgw*$imgh;

        $colors = array();

        for ($i=0; $i<$imgw; $i++) {
            for ($j=0; $j<$imgh; $j++) {

                $rgb = ImageColorAt($im, $i, $j);
                $r = ($rgb >> 16) & 0xFF;
                $g = ($rgb >> 8) & 0xFF;
                $b = $rgb & 0xFF;

                $c = $this->getClosest(array($r, $g, $b));

                if ($c == "white") continue;

                if (isset($colors[$c])) {
                    $colors[$c]++;
                } else {
                    $colors[$c] = 1;
                }
            }
        }

        arsort($colors);

        return $colors;
    }
}

$x = new Image;
print_r($x->getImageColors("http://www.stilsos.com/temp/resized/product-310863-x2.jpg"));