How can I add metadata to an image?

Question

Where does one insert meta data into and image file and what it the mark up to do so? i want to do this with php.

Answer 1

I recently saw a really cool article on the w3c blog about combining RDFa and an HTML <imagemap> to enrich images by specifying not only what's in the image but also where it is in the image: http://www.w3.org/QA/2008/01/rdfa_and_html_imagemap.html