On Sun, Sep 14, sionvalais inscribed on the eternal scroll:
Is it possible to prevent caching of images on a website
Yes...
when one uses xhtml strict?
I'm not sure why you think the markup language plays any role.
Images don't have "meta tags".
http://www.mnot.net/cache_docs/ may be informative.
I suspect an "XY" problem: for what purpose have you decided that you
want to wreck this normally useful feature of the web?