%20 is a encoded space. you cannot use non-latin laters and some special characters (including spaces) in the addresses, without encoding them first
[EDIT]
ops...my cellphone didn't show the correct text...didn't see the - in your request.
try replacing
$row['image_name'] = strtr($row['image_name'], "éèêàëâúóíáABCDEFGHIJKLMNOPQRSTUVWXYZ","eeeaeauoiaabcdefghijklmnopqrstuvwxyz");
with:
$row['image_name'] = strtr($row['image_name'], "éèêàëâúóíáABCDEFGHIJKLMNOPQRSTUVWXYZ ","eeeaeauoiaabcdefghijklmnopqrstuvwxyz-");