<?php
    $path = $_SERVER['DOCUMENT_ROOT'] . '/images/';
    $images = scandir($path);
    if (false !== $images) {
            $images = preg_grep('/\\.(?:png|gif|jpe?g)$/', $images);
            foreach ($images as $image) {
                echo '<img src="/images/', htmlspecialchars(urlencode($image)),'"/>';
            }
    }
?>