char.png

index.php

<?php
include 'WideImage/WideImage.php';
include 'Skin.php';

# setup uri
$uri = str_replace(".png", "", explode('/', trim($_GET['q'], '/')));

# is retina?
$retina = strpos($uri[count($uri) - 1], "@2x");
$uri = str_replace("@2x", "", $uri);

# setup variables
$username = $uri[0] == null ? 'char' : $uri[0];
$size = $uri[1] == null ? '32' : $uri[1];


if($size > 1024) {
    $url = '//' . $_SERVER["SERVER_NAME"] . $_SERVER["REQUEST_URI"];
    $url = str_replace($size, "1024", $url);

    die(header('Location: ' . $url));
}

if($retina) $size = $size * 2;

# get skin
$result = Skin::get($username);
$img = $result[0];
$mime = $result[1];

# has helmet?
$bg = $img->getColorAt(0,0);
$hasHelmet = hasHelmet($img, $mime);

function hasHelmet($img, $mime) {
    if($mime != "image/png") return false;

    for($i = 0; $i < 8; $i++) {
        for($j = 0; $j < 8; $j++) {
            $color = $img->getRGBAt(40 + $i, 8 + $j);
            if($color['red'] == 255 && $color['green'] == 255 && $color['blue'] == 255 && $color['alpha'] == 0) continue;
            if($color['alpha'] < 127) return true;
        }
    }

    return false;
}

# setup helm if has helmet
if($hasHelmet) {
    $helm = $img->crop(40, 8, 8, 8);
}

# crop image to just head
$head = $img->crop(8, 8, 8, 8);

# merge head and helm if has helm
if ($hasHelmet) {
    $head = $head->merge($helm);
}

# resize and show the result
$final = $head->resize($size);
$final->output(".png");
?>

Skin.php

<?php
class Skin {
    public static function get($username) {
        $steve = in_array(strtolower($username), array("steve", "player", "default"));
        if(!$steve) $contents = self::fetch('http://skins.minecraft.net/MinecraftSkins/' . $username . '.png');
        $defaultImage = WideImage::load("char.png");
        $defaultType = "image/png";

        if ($steve || $contents === false) {
            $img = $defaultImage;
            $type = $defaultType;
        } else {
            try {
                $img = WideImage::load($contents);

                $finfo = new finfo(FILEINFO_MIME_TYPE);
                $type = $finfo->buffer($contents);
            } catch (Exception $e) {
                $img = $defaultImage;
                $type = $defaultType;
            }
        }

        return array($img, $type);
    }

    private static function fetch($url) {
        $handle = curl_init($url);
        if (false === $handle) {
            return false;
        }

        curl_setopt($handle, CURLOPT_HEADER, false);
        curl_setopt($handle, CURLOPT_FOLLOWLOCATION, true);
        curl_setopt($handle, CURLOPT_FAILONERROR, true);  // this works
        curl_setopt($handle, CURLOPT_HTTPHEADER, Array("User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.8.1.15) Gecko/20080623 Firefox/2.0.0.15")); // request as if Firefox
        curl_setopt($handle, CURLOPT_RETURNTRANSFER, true);
        curl_setopt($handle, CURLOPT_TIMEOUT_MS, 1000);

        $contents = curl_exec($handle);

        curl_close($handle);
        return $contents;
    }
}
?>