nelson_p@apollo.uucp (05/03/88)
I have a question on a graphics topic that is not sexy or
flashy like fractals or ray-tracing or NURBS but nevertheless
has practical significance.
At home I have a PC with 'hercules-compatible' monochrome graphics.
I have been considering getting accounts on Compuserve and perhaps
on some other online databases such as Dialog. One of the things
I've noticed about these services is that, even if they call them-
selves 'information services', their definition of information is
rather narrowly limited to ASCII text.
A lot of information is better presented graphically. And a lot of
graphical information does not require shading or high resolution.
Graphs, charts, pinouts, maps, parts diagrams, simple schematics
and a lot of other information can be easily represented with simple
2D line drawing. A simple command set of moves, draws, filled
polygons, text, linestyles and textstyles and maybe patterned fills
or color setting for those systems that can support it would be all
that would be necessary. The average subscriber to these services
probably has at least a PC with mono graphics, CGA or EGA or he has
a Mac. At 1200 baud a simple, low res image of a few hundred line
segments and maybe a little text could be sent in a matter of seconds.
So why don't we see more use of graphics in online databases? Is the
main problem one of getting the graphical information into the data-
base in the first place? Or is there no standard of the type I suggested
above? (actually this is a good question: IS there such a standard?)
Or do people involved in this kind of stuff not recognize the value of
representing information graphically? Is anyone looking at these kinds
of issues?
Thank you in advance.
--Peter Nelson
paul@hpldola.HP.COM (Paul Bame) (05/04/88)
About the "standard" format for graphical images. The GIF format was developed (or licensed) by Compuserve so there's definitely a standard there. For more details about GIF, see recent postings in rec.arts.startrek. It is basically a compressed bitmap image - not the same kind of thing you were thinking about (which I'd like too - for Un*x mail if nothing else). It uses LZW compression and reasonable-sized images tend to be about 11-14 Kbytes (digitized B&W photos 640x400 I think) which makes transfer at 1200 baud not too bad. --Paul Bame
webber@constance.rutgers.edu (Bob Webber) (05/06/88)
In article <3bd128e8.44e6@apollo.uucp>, nelson_p@apollo.uucp writes: >... > A lot of information is better presented graphically. And a lot of > graphical information does not require shading or high resolution. > Graphs, charts, pinouts, maps, parts diagrams, simple schematics > and a lot of other information can be easily represented with simple > 2D line drawing. A simple command set of moves, draws, filled > polygons, text, linestyles and textstyles and maybe patterned fills > or color setting for those systems that can support it would be all > that would be necessary. The average subscriber to these services > probably has at least a PC with mono graphics, CGA or EGA or he has > a Mac. At 1200 baud a simple, low res image of a few hundred line > segments and maybe a little text could be sent in a matter of seconds. > > So why don't we see more use of graphics in online databases? Is the > main problem one of getting the graphical information into the data- > base in the first place? Or is there no standard of the type I suggested > above? (actually this is a good question: IS there such a standard?) > Or do people involved in this kind of stuff not recognize the value of > representing information graphically? Is anyone looking at these kinds > of issues? Actually there are a number of usable standards (NAPLAS, Tek4014, CGM, Unix Plot, being a few that come to mind). Of these, Tek4014 is the one most likely to be supported by a home computer although I don't think it is a standard option on any of them. However, the general availabilty of 1200baud or higher modems and consumer computers that supported Tek4014 graphics is much more recent than the set up of the major online databases you refer to (i.e., at the time they were set up such graphics was less plausible and now they probably would have to do quite a bit of work to upgrade their services to a point where a graphics capability was visible to the average user). There is also a question of setting things up so that people can easily create data in this format (it is almost always easier to type a page full of text than to make just one well-done figure and integrate it into the text (whether one uses computer-aided drawing technology or not)). The computational issues involved are still poorly understood. For example, it was recently shown that figuring out how to lay out a piechart so that the labels to all the regions fit nicely inside the regions rather than crossing the borders or sitting at odd angles (and assuming fixed size character sets) is NP-hard [ref: D. L. Souvaine and C. J. Van Wyk, ``How hard can it be to draw a pie chart,'' Technical Report LCSR-TR-90, Department of Computer Science, Rutgers University, New Brunswick, New Jersey, May 1987]. ----- BOB (webber@athos.rutgers.edu ; rutgers!athos.rutgers.edu!webber)
lowey@sask.UUCP (Kevin Lowey) (05/12/88)
In article <3bd128e8.44e6@apollo.uucp>, nelson_p@apollo.uucp writes: > > I have been considering getting accounts on Compuserve and perhaps > on some other online databases such as Dialog. One of the things > I've noticed about these services is that, even if they call them- > selves 'information services', their definition of information is > rather narrowly limited to ASCII text. > > A lot of information is better presented graphically. > So why don't we see more use of graphics in online databases? COMPUSERVE has developed a standard called Graphics Interchange Format. It can be used two ways. The first is you download a file, then use a GIF viewer to display the image on your screen. The image is stored in a device independant way, so it can be displayed on many different devices. Unfortunately the only one I've seen so far is for EGA cards. The second way is to use it online. The picture is decoded "on the fly" by your terminal emulator. Unfortunately you need a special emulator to do this. I haven't seen any terminal programs which have this emulator in them. There are other standards. For example, the NAPLAPS (sp?) standard for systems like Telidon use a standard for low resolution colour images similar to the displays shown on some cable TV information channels. Simple pictures could be developed from circles, lines, etc. The user uses a number pad to select different "screens" which contain more information like bus schedules, good restaurants, stock prices, etc. Here in Saskatchewan the telephone company has a service called AGRITEX based on this system, for use by the farming industry and other interested people. There is also the ANSI METAFILE standard. This has been developed to allow the transfer of graphic images to different programs. For example, Lotus Freelance can create META files that can be read by Lotus Freelance and included in documents. I'm awaiting a driver for our VAX/VMS TELL-A-GRAF program which will allow it to use ANSI-METAFILES, thus allowing vertical integration of Micro and Mainframe graphics systems. So in other words, the standards exist, and are being used. Kevin Lowey -- University of Saskatchewan Computing Services
mae%vygr@Sun.COM (Mike Ekberg, Sun {Graphics Product Division}) (05/21/88)
Probably the wrong group to follow up on this, but here goes. You should look into Postscript as your PDL(Page Description Language). Sun has choosen (and extended) Postscript as basis for NeWS. An interesting NeWS demo is an Atari ST acting as a NeWS server via RS-232. Is Postscript a standard? Seems to be for printers, at least. mike (sun!mae), M/S 5-40 "There's nothing human that's alien to us." - A. Einstein