Some answers mention that it's possiblepossible to injectinject attacker-controlled HTML into images and therefore provoke XSS.
I guess that this HTML will be processed by browser only if hole exists in browser. So I think it's more a browser issue and there is no need to convert those images, strip EXIF metadata, randomize them at web-application's side.
Is attacker able to inject HTML into image that will provoke XSS? If yes, how?