Immagini da cartella

<?php
    function genera_codice_immagini()
    {
        $files = glob("immagini/*.[jJ][pP][gG]");
        foreach ($files as $image) {
            echo '<a href="'.$image.'"> <img src="'.get_thumb(basename($image)).'" width="75" height="75" alt=""/></a>';
        }
    }

    function create_thumb($imagename)
    {
        $thumbnail = imagecreatetruecolor(75, 75);
        $source = imagecreatefromjpeg("immagini/".$imagename);
        imagecopyresized($thumbnail, $source, 0, 0, 0, 0, 75, 75, imagesx($source), imagesy($source));
        header('Content-Type: image/jpeg');
        imagejpeg($thumbnail, "thumbnails/".$imagename);
    }

    function get_thumb($imagename)
    {
        if (file_exists("thumbnails/".$imagename))
        {
            /* niente */
        } else {
            create_thumb($imagename);
        }
        return "thumbnails/".$imagename;
    }
    genera_codice_immagini();
?>