[Groff] Inline Images

[Paul O'Leary McCann]

Is there any standard way of putting images inline? Sparklines aren't
what I had in mind, but they're an example of the sort of thing I'd like
to be able to do.

http://en.wikipedia.org/wiki/Sparkline

I've usually used the PSPIC macro when I need to insert and image,
though I've occasionally used Heirloom troff's requests, but if there's
a way to get either of them to inline images I haven't figure it out.
-POLM