function my_rename($dirname)  

{  

    $ext_arr = array('jpeg', 'jpg', 'gif');  

    $dir = opendir($dirname);  

    $count = 1;  

    while (($file = readdir($dir)) !== false) {  

        if (is_file($dirname . '/' . $file)) {  

            $info = pathinfo($dirname . '/' . $file);  

            if (in_array(strtolower($info['extension']), $ext_arr)) {  

                rename($dirname . '/' . $file, $dirname . '/' . str_pad($count, 3, '0', STR_PAD_LEFT) . '.' . strtolower($info['extension']));  

                $count ++ ;  

            }  

        } elseif (is_dir($dirname . '/' . $file) && $file != '.' && $file != '..')my_rename($dirname . '/' . $file);  

    }  

    closedir($dir);  

}