Pictures & HTML

Dave_Raggett (
Mon, 23 Nov 92 15:29:11 GMT

From: Dave_Raggett <>
Message-Id: <>
Subject: Pictures & HTML
Date: Mon, 23 Nov 92 15:29:11 GMT

>> The client doesn't know in advance about these embedded objects, it
>> therefore makes sense for the server to be able to append them to the
>> requested html document so as to avoid a further network loop delay for
>> retrieving them.

> I've been through this line of thought in a hypertext/electronic book
> project. Yes, it's more efficient to include the graphics in the HTML data
> stream, but only if you just have one version (format) for each graphic.

I wasn't suggesting including the graphics as part of the HTML data stream,
but rather appending it as a separate object with its own distinct format, as
appropriate to its particular type.

> We found it best in the long run to provide our embedded graphics in several
> formats, and allow the client to choose the format most appropriate for its
> output device (e.g. 8-bit vs 24-bit colour, Postscript if the device
> supports it, WMF if the client is running the Microsoft Windows version of
> the viewer program, etc).

This seems to be where the negotiation idea comes in. The client can tell
the server in advance (or as part of the request) what its capabilities are.
Given this the server can work out the most appropriate format to send.

If the picture is really big, or the server has to do some time consuming
format conversion (or perhaps ask some agent to do this on its behalf),
then I believe that the server should quickly reply with a short message to
that effect so that the user has some idea of what is happening and how long
to expect to wait.

By the way, you may be interested to know that in Britain, universities are
being connected this spring to a new fiber optic network intended to allow
academics to read electronic journals on-line with video clips, 3-D animations
and simulations. It will be possible for distant researchers to work on the
same data or paper simultaneously and see each other's changes.

I will try to find out more.

Best wishes,

Dave Raggett