PHP Save Base64 String As Image

<?php
    define('UPLOAD_DIR', 'images/');
    $image = 'base64stringhere';
    $image = str_replace('data:image/png;base64,', '', $image);
    $image = str_replace(' ', '+', $image);
    $data = base64_decode($image);
    $file = UPLOAD_DIR . uniqid() . '.png';
    $success = file_put_contents($file, $data);
    print $success ? $file : 'error';
?>