It's quite common to run Tomcat behind Apache. In Apache you can then direct certain URLs to Tomcat, and have Apache/PHP handle the others (including the static images).
(On Unix, Tomcat itself cannot securely made to run on port 80, while Apache can. Tomcat, being a Java process, would be required to run as root, while Apache will switch to non-root privileges as soon as port 80 has been claimed. So, running Apache on port 80 and have it redirect some or all requests to Tomcat, is quite common on Unix.)