This snippet is just an upgrade to the "http://snipplr.com/view/7396/php-file-extension-case-changer/" code. This particular code works on image files... although you can just change this line [if (preg_match("/(jpg|gif|png|bmp)/",$ext)) ] to target a specific filetype. ciao! hope this piece of code can help you as it has helped me. :)