Re: son of X-Face:

Paul Smith (
Tue, 17 Aug 93 09:22:17 EDT

[] Regarding son of X-Face:;
[] (James Ashton) writes:

ja> Resolution. Almost certainly still 48x48.

I'm afraid I agree with Jamie and Rich on this, *especially* if you're
going to be generating an RFC (which I think is a great idea): I don't
think we should mandate an icon size.

Definitely suggest one, and make it the default, and even go so far as
to tweak the compression for a certain size (or maybe use a tuned
algorithm for 48x48 or 64x64, and a generic algorithm for larger ones?)
But it seems a bit short-sighted on our part if we seriously restrict
the size.

Face display programs can offer the user a choice of how to do displays,
which is where you want that choice anyway: the viewer can crop, shrink,
display full-size, or not display large faces at all. You could even
have a viewer that shrunk the icon, then if you clicked on it it would
pop up the full face. Or whatever.

The point is, the sender should send what he wants and the viewer should
view what she wants.

ja> I'm assuming existing standards (JPEG comes to mind) are
ja> unsuitable for this purpose. Please let me know if not and
ja> save me lots of work.

I third or fourth the vote to examine XPM; we used this for icons at my
last job to excellent effect. A very nice package.

ja> Backward compatibility is impossible without choosing a new
ja> header title, say `X-Image'. Should an old style, one bit
ja> image be available from an `X-Image' along with a colour
ja> version or should we just include both an `X-Image' and an
ja> `X-Face'.

I think Jamie is correct: the best thing would be to find a way to make
old vs. new detection automatic.

Also, the new X-Face spec should imbed some kind of version info so the
compression algorithm, etc. can be updated and not break everything
(except you'd need a new viewer--but old viewers could handle this
relatively gracefully with a message or special icon or something).

/ \
Paul D. Smith | That's the thing about being a boxer:
<> | even when you're at the top of your field,
Wellfleet Communications, Inc. | people still hit you in the head.
Network Management Development | -- Paula Poundstone