Artigo/Tutorial sobre upload seguro de imagens

fiz um script baseado em algumas pesquisas...existe algo a mais pra acrescentar ou fazer de forma diferente?

if(isset($_FILES["file"]) && $_FILES["file"]['error'] == 0)
{

$file = $_FILES["file"];

 $file = $_FILES["file"]['name'];
 $file_type = $_FILES["file"]['type'];
 $file = strtolower($file);
 $file_type = strtolower($file_type);

 if(is_array($_FILES["file"]['error'])){
 echo '<a href="cad_p.php">Try again</a>';
 echo "<br/>";
 echo "<br/>";
 die('Erro: Only one file accepted');
 }

 $max_file_size = 2097152;
 if($_FILES['file']['size'] >= $max_file_size || $_FILES['file']['size'] == 0){
 echo '<a href="cad_p.php">Try again</a>';
 echo "<br/>";
 echo "<br/>";
 die('Erro: file size exceeded (2mb)');
 }

 /* check if contain php */
 $pos = strpos($file, 'php');
 if(!($pos === false)) {
 echo '<a href="cad_p.php">Try again</a>';
 echo "<br/>";
 echo "<br/>";
 die('Error: image has php script');
 }

 /* get file extension */
 $file_ext = strrchr($file, '.');

 /* check if it is allowed */
 $allowed = array(".jpg",".jpeg",".png");
 if (!(in_array($file_ext, $allowed))) {
 echo '<a href="cad_p.php">Try again</a>';
 echo "<br/>";
 echo "<br/>";
 die('Extension not allowed');
 }

 /* check upload type */
 $pos = strpos($file_type,'image');
 if($pos === false) {
 echo '<a href="cad_p.php">Try again</a>';
 echo "<br/>";
 echo "<br/>";
 die('error 1: Mime type not valid');
 }

 $imageinfo = getimagesize($_FILES['file']['tmp_name']);
 if($imageinfo['mime'] != 'image/jpeg'&& $imageinfo['mime'] != 'image/jpg'&& $imageinfo['mime'] != 'image/png') {
 echo '<a href="cad_p.php">Try again</a>';
 echo "<br/>";
 echo "<br/>";
 die('error 2: size mime type not valid');
 }

 //check double file type (image with comment)
 if(substr_count($file_type, '/')>1){
 echo '<a href="cad_p.php">Try again</a>';
 echo "<br/>";
 echo "<br/>";
 die('error 3: double type');
 }

 /* upload to upload direcory */
 $uploaddir = 'up_files/';

 if (file_exists($uploaddir)) {
 } else {
mkdir( $uploaddir, 0777);
}

$uploadfile = $uploaddir . md5(basename($_FILES['file']['name'])).$file_ext;

if (move_uploaded_file($_FILES['file']['tmp_name'], $uploadfile)) {
 echo "";

 echo "Error moving image file";
 echo '<a href="cad_p.php">Try again</a>';
}

$name = $_POST['name'];

if ($insert_stmt = $mysqli->prepare("INSERT INTO products (name, file) VALUES (?, ?)")) {$insert_stmt->bind_param('ss', $name, $uploadfile);

if (! $insert_stmt->execute()) {

 echo '<div class="register_success">';
 echo "Could not insert...";
 echo '</div>';

 echo '<div class="register_success">';
 echo "Product Insert success...";
 echo '</div>';
}

}
}

echo '<a href="cad_p.php">Tente novamente</a>';
echo "<br/>";
echo "<br/>";
die('No image file selected');
}