function contact_photo($args)
    {
        // pre-conditions, exit if photo already exists or invalid input
        if (!empty($args['url']) || !empty($args['data'])
            || (empty($args['record']) && empty($args['email']))
        ) {
            return $args;
        }

        $rcmail = rcmail::get_instance();

        // supporting edit/add action may be tricky, let's not do this
        if ($rcmail->action == 'show' || $rcmail->action == 'photo') {
            $email = $args['email'];
            if (!$email && $args['record']) {
                $addresses = rcube_addressbook::get_col_values('email', $args['record'], true);
                if (!empty($addresses)) {
                    $email = $addresses[0];
                }
            }

            if ($email) {
                require_once __DIR__ . '/identicon_engine.php';

                $identicon = new identicon_engine($email);

                if ($rcmail->action == 'show') {
                    // set photo URL using data-uri
                    if (($icon = $identicon->getBinary()) && ($icon = base64_encode($icon))) {
                        $mimetype    =$identicon->getMimetype();
                        $args['url'] = sprintf('data:%s;base64,%s', $mimetype, $icon);
                    }
                }
                else {
                    // send the icon to the browser
                    $identicon = new identicon_engine($email);
                    if ($identicon->sendOutput()) {
                        exit;
                    }
                }
            }
        }

        return $args;
    }