A friend was helping, this is the solution:
Link "Display all images added by xxx" in details.html.
Link "Alle Bilder von xxx anzeigen" in details.html.
includes/functions.php
find
$site_template->register_vars(array(
"image_id" => $image_row['image_id'],
After
"lang_show_user_images" => "<a href=\"".$site_sess->url(ROOT_PATH."search.php?search_user=".urlencode($user_name))."\">".preg_replace("/".$site_template->start."user_name".$site_template->end."/siU", $user_name, $lang['show_user_images'])."</a>",
templates/default/details.html
insert
{lang_show_user_images}
Done