HTML and bitmaps (Jim Davis)
Date: Wed, 3 Jun 92 15:56:01 EDT
From: (Jim Davis)
Message-id: <>
Subject: HTML and bitmaps
I would like to include non-text data (e.g. bitmaps, sound)
in my hyperdocuments.

One way to do this would be:

1) extend HTML to allow for such data, e.g.  a tag like
<BITMAP height=100 width=100 encoding=FAXG4>

(I think the WWW protocols would require that the data be uuencoded,
since I don't think they will allow 8bit data)

2) extend Viola (my WWW browser of choice) to recognize
this tag and do the right thing with it, i.e. uudecode it then
start a display program (or place the bitmap into the

A related generalization would be if the browsing program were able to
choose among a set of alternative display programs based on the "type"
of the document linked to.  In this case, I could have an anchor
that pointed to a bitmap file in addition to (or instead of) placing
bitmaps within HTML files.

This sort of thing is possible in both WAIS and MetaMail.  In document
has a type known to the WAIS server, the client inspects this type and
selects a display program according to the values in the Xwais.filters
X resource; In MetaMail each piece of mail is labeled with an explicit
type; MetaMail consults the mailcap file to determine how to display
each type.

I see that anchors in WWW can have a TYPE attibute, but I can't tell
whether this is the type of the link or of the thing linked to.  If
the former, then I see no easy way to do it in WWW, short of adding
the facility to Viola to decide the document type by inspecting it
(e.g. looking for magic header bits which at least some data formats

I would be grateful for your comments on this matter.

best wishes