Sanitize File Names like Titles in WordPress

ppp-sanitize-file-names.php

<?php
/*
Plugin Name: Sanitize File Names
Description: extend file name sanitization
Author: Gabriele Lässer
Version: 1.0
*/

function pppf_extend_filename_sanitization( $title ) {

	if ( seems_utf8( $title ) ) {	
		$chars[ chr(195).chr(132) ] = 'Ae';
		$chars[ chr(195).chr(164) ] = 'ae';
		$chars[ chr(195).chr(150) ] = 'Oe';
		$chars[ chr(195).chr(182) ] = 'oe';
		$chars[ chr(195).chr(156) ] = 'Ue';
		$chars[ chr(195).chr(188) ] = 'ue';
		$chars[ chr(195).chr(159) ] = 'ss'; 
		$chars[ chr(195).chr(134) ] = 'Ae';
		$chars[ chr(195).chr(166) ] = 'ae';
		$chars[ chr(195).chr(152) ] = 'Oe';
		$chars[ chr(195).chr(184) ] = 'oe';
		$chars[ chr(195).chr(133) ] = 'Aa';
		$chars[ chr(195).chr(165) ] = 'aa';
		$title = strtr( $title, $chars );
	}	

	return strtolower( remove_accents( $title ) );
	
}
add_filter( 'sanitize_file_name', 'pppf_extend_filename_sanitization' );