Upload an img and store it locally

cleanup.php

#!/usr/bin/php
<?php

$dir = 'tmp/';
$files = scandir($dir);
$delay = time() - 2*60;

foreach($files as $file) {
        if(strpos($file, '.png') !== false && filemtime($dir.$file) <= $delay) {
                echo $dir.$file."\n";
                unlink($dir.$file);
        }
}

?>

img.php

<?php

ob_start("ob_gzhandler");

function loadImage ($file) {
    $data = getimagesize($file);
    switch($data["mime"]){
        case "image/jpeg":
            $im = imagecreatefromjpeg($file);
            break;
        case "image/png":
            $im = imagecreatefrompng($file);
            break;
        case "image/gif":
            $im = imagecreatefromgif($file);
            break;
        default:
            throw new Exception('Img Type not managed');
    }
    return $im;
}

if (isset($_GET['url']) || (isset($_FILES['img']) && !$_FILES['img']['error'] && is_uploaded_file($_FILES['img']['tmp_name']))) {
        if (isset($_GET['url'])) {
                $file = $_GET['url'];
        } else {
                $file = $_FILES['img']['tmp_name'];
        }

        try {
            $image = loadImage($file);
        } catch(Exception $e) {
            die('Unable to load this image');
        }

        $w = imagesx($image);
        $h = imagesy($image);

        $im2 = ImageCreateTrueColor($w, $h);
        imagecopyResampled ($im2, $image, 0, 0, 0, 0, $w, $h, $w, $h);

        $time = @filemtime($file);
        if ($time === null) {
                $time = time();
        }

        $filename = 'tmp/'.md5($file.md5('clevercover-salt')).'.png';
        imagepng($im2, $filename);
        imagedestroy($im2);
        imagedestroy($image);

        echo substr($_SERVER["PHP_SELF"], 0, strrpos($_SERVER['PHP_SELF'], '/')).'/'.$filename.'#'.time();
} else if (isset($_POST['src'])) {
        $src = $_POST['src'];

        header('Content-Type: image/png');
        header("Content-Disposition: attachment; filename=".md5($src).".png");
        header('Last-Modified: ' . gmdate('D, d M Y H:i:s', time()) . ' GMT');
        header("Cache-Control: public");
        header("Pragma: public");

        $uri =  substr($src, strpos($src,",") + 1);
        $im2 = imagecreatefromstring(base64_decode($uri));
        imagepng($im2);
        imagedestroy($im2);
} else {
        die('USAGE: img.php?url=&lt;imageURL&gt; or img.php + by POST src=&lt;base64&gt;');
}