Why does mod_pagespeed compress images rendered using <h:graphicImage>
but not images using <img>
.
For example: Doesn't get compressed:
<img src="/resources/img/logo.png" alt="Logo" height="50" width="230" />
This does get compressed:
<h:graphicImage library="img" name="logo.png" alt="Logo" height="50" width="230" />
mod_pagespeed will only compress cacheable images:
https://developers.google.com/speed/pagespeed/module/faq#not-rewriting