HDTenEightyP/NetNews huggingface dataset:
From: galt%peruvian.utah.edu@cs.utah.edu (Greg Alt)
Subject: Re: Source for random ascii stereogram generator
Date: 29 Aug 92 16:41:59 MDT
Reply-To: galt%peruvian.utah.edu@cs.utah.edu
Organization: University of Utah, CS Dept., Salt Lake City
Distribution: usa

In article <1992Aug24.195741.21281@awdprime.austin.ibm.com>, coleman@casey.austin.ibm.com writes:
>Sorry if one has already been posted, but here is a quick
>random ascii stereogram generator that reads a datafile.
>I was concentrating more on function than coding style.
>No checking is done on the data file, so for best results,
>use only columns 15-60, rows 3-17 and "figures" at least 3 characters
>wide and 2 characters tall.

Here is an easier to read version of the one I posted a while ago.
You have to redirect the input like this:  stereo < mask
It works with any number of rows vertically, and the rows in the
mask should be 64 or less characters.  The do-while loop is to
prevent duplicate characters (e.g. ZZ) which can hurt the 3D effect.
------------
#include <math.h>
#include <stdio.h>
/* stereo.c by galt@peruvian.utah.edu */
main()
{
   char mask[81],out[81],shift,i;

   /* print line at top to use as a guide for viewing */
   printf("%31sX%15sX\n","","");

   /* read in each mask until end of input */
   while(gets(mask)!=NULL)
   {
      /* wipe unused part of mask */
      for(i=1;i<80;i++)
        if(mask[i-1]==0) mask[i]=0;

      /* create output string one character at a time */
      for(out[80]=shift=i=0;i<80;i++)
      {
         /* character is random if it comes right after a shifted portion */
         /*   or if it is in the first 16 characters */
         if((shift && mask[i-16]!='#') || i<16)
         {
            shift=0;
            /* random character between 'A' and 'z' */
            do
              out[i]=random()%('z'-'A')+'A';
            while(out[i]==out[i-1] || out[i]==out[i-15]) ;
         }
         else
         {
            /* if the mask character is a '#' then shift */
            shift=(mask[i-16]=='#')?1:0;
            /* copy the character from previous column, shifting if necessary */
            out[i]=out[i-16+shift];
         }
      }
      /* print line */
      puts(out);
   }
}
------------
----
"Dwayne Dibly?!" - The Cat (I've seen 5th season.  Have you?)
----
From: rick@tekig1.PEN.TEK.COM (Fredrick Wilson)
Newsgroups: alt.3d
Subject: Re: Stereo gif(s) posted
Date: 25 Aug 92 21:47:50 GMT
Organization: Tektronix, Inc., Beaverton,  OR.

In article <1992Aug24.165821.22004@crd.ge.com> davidsen@crd.ge.com (bill davidsen) writes:
>I posted one stereo gif to alt.binaries.pictures.misc last night,
>several more to follow. Enjoy.
>-- 


The more, the better.  But would someone who has access to them please
FTP them to sugrfx.acs.syr.edu /pub/incoming   so the millions of us
who don't get alt.binaries.pictures.* can get to them...please,please.

Or FTP them to somewhere else, as long as you let us know.

To motivate someone to put them on sugrfx I have just loaded a
pair of files (StHelens_l.gif StHelens_r.gif) into /pub/incoming
which are a stereo pair of an orbital view of the crater in
Mt. St. Helens.  They might get moved to /pub/vr/3d any time.


      Rick   Wilson             Rick Wilson       Cross-eyed STEREO
      --------------           --------------
     |       O      |         |      O       |
     |    O         |         |     O        |    rick@sable.pen.tek.com
     |              |         |              |    Tektronix
     \    _     O   |         |\    _  O     |    Beaverton, Orygun
     |\  /      _   |         | \  /   _     |
     | \/   \  /    |         |  \/\  /      | 
      --------------           --------------      
Newsgroups: alt.3d
From: lau@femto.cs.umn.edu (Patrick Lau)
Subject: what to see in a picture stereogram?
Organization: University of Minnesota
Date: Wed, 26 Aug 1992 19:44:58 GMT

What are we supposed to see in the picture stereograms? I have tried the
usual split/corss eye methods, and all that I see is (say for the lena
picture) six lenas on the background, and some kind of "hollow tube"
extending outwards, with the lena pictures on the inside of the tube.
What is so interesting about this? Or did I see the wrong thing the
wrong way?

Patrick
Newsgroups: alt.3d
From: timk@meaddata.com (Tim Klein)
Subject: Re: TV Snow tornado (was Re: 3-D TV snow)
Organization: Mead Data Central, Dayton OH
Date: Thu, 27 Aug 1992 13:58:27 GMT

In article <740@capmkt.COM>, charles@capmkt.COM (Charles Neveu) writes:
|> 
|> Another interesting effect was demonstrated to me by Scott Stevenson
|> and Larry Cormack here at U.C. Berkeley. Get a Dove prism (a type of
|> prism which rotates images about the "visual" axis). Put the prism in
|> front of one eye and turn it so that the image in that eye is slightly
|> cyclorotated with respect to the image in the unaided eye. Now view a
|> TV snow screen and fuse the two images. A tornado-like swirl will
|> appear, tilted either in or out of the plane of the screen, depending
|> on the direction of the relative tilt of the images.

Where might I get such a prism?  Are they expensive?



===========================================================================
Timothy Klein                 I wish I had a kryptonite cross.  Then I
timk@meaddata.com             could keep both Dracula AND Superman away.
...!uunet!meaddata!timk                               -- Jack Handey
Newsgroups: alt.3d
From: bteo@tartarus.uwa.edu.au (Teo Boon Cheang)
Subject: Stereogram
Organization: University of Western Australia
Date: Sun, 30 Aug 1992 04:02:41 GMT

I'd get flamed for this! *frequently asked question maybe?*

I have problem seeing steoreo stuff .. via crosseyes?
\
What ya mean by crosseye anyway, I tried to "fuse" the 2 pictures
together but i got a headache instead!

Help appreciated
From: rick@tekig1.PEN.TEK.COM (Fredrick Wilson)
Newsgroups: alt.3d
Subject: Re: How do I generate the two views for a 3d image (LCD glasses)
Date: 27 Aug 92 20:31:29 GMT
Organization: Tektronix, Inc., Beaverton,  OR.

In article <BtnIzJ.GGJ@ie.utoronto.ca> drascic@ie.utoronto.ca (SpIke) writes:
>gold@imp.sim.es.com (Bruce Gold) writes:
>
>>In article <busey.714845002@milton>, (Thomas Busey) writes:
>>|> 
>>|> 2) dolly the camera left or right perpendicular to "forward" 3) dolly one way 
>
>>The prize is behind door number 2.  
>
>Parallel camera models, such as the one you are
>suggesting, place the graphics in an area IN FRONT OF the monitor.

Placement of grapics in front or in back of the monitor is not a
function of camera convergance.  It's a function of stereo window placement.
With any picture, with any camera method, you can move the grapics up to
your nose or way off in the distance by adjusting the stereo window
(i.e. cropping the edges properly). 

When you make a stereo picture you are not trying to reproduce what
the eye sees.  You are trying to reproduce reality, so the eye can see
it properly. Reality is parallel, not converged.  With parallel cameras
your eyes can then converge on any part of the picture.  With converged
cameras you have told the eyes that they should converge in only one
place to see a proper picture.  If the eyes try to converge elsewhere
in the picture then they are doing a "double transform", so to speak,
and they see a distorted picture.

Parallel cameras are correct, and stereo window manipulation is
usually needed.  My .sig is an example of how a parallel view can
be put in front or in back of the window.
As is this:

   ---.  ---   --- . ---
   --- . ---   --- . ---
   ---  .---   --- . ---



      Rick   Wilson             Rick Wilson       Cross-eyed STEREO
      --------------           --------------
     |       O      |         |      O       |
     |    O         |         |     O        |    rick@sable.pen.tek.com
     |              |         |              |    Tektronix
     \    _     O   |         |\    _  O     |    Beaverton, Orygun
     |\  /      _   |         | \  /   _     |
     | \/   \  /    |         |  \/\  /      | 
      --------------           --------------
From: busey@milton.u.washington.edu (Thomas Busey)
Newsgroups: alt.3d
Subject: How do I generate the two views for a 3d image (LCD glasses)
Date: 26 Aug 92 16:03:22 GMT
Organization: University of Washington


  I'm designing a stereo VR system to do some psychology research on the
contribution of depth information for the perception of direction and
speed of motion. 

  I'm using a (low-tech, I know) Mac II with a graphics system that gives
me control over the "camera" of a 3-d presentation system.  I can
control position, yaw, pitch, roll, focal length, etc. of the eye.
 
  My question is how to generate the left and right images for a
stereo display.  Three transforms come to mind:  1) pan the "camera" left
and right about 10 degrees (or less) 2) dolly the camera left or right
perpendicular to "forward" 3) dolly the camera one way and pan back the
other simultaneously, which I think is what they eyes do relative to the
nose.  I may be missing the actual transform entirely- I haven't given this
too much thought yet. 

  I've read that local transforms of the objects such as local rotations
introduce distortions such as vertical parallax.  This doesn't sound like
a good solution.

  Since this is obviously still a point of active discussion, I thought
I'd post to alt.3d.  It may be the answer depends on the
application, in which case I want to simulate the view from each eye as
close as possible- not necessarily come up with the most informative or
least straining design, although all three may coexist.

  Any suggestions?
Tom Busey
busey@u.washington.edu
Department of Psychology
Newsgroups: alt.3d
Subject: Re: Anyone using XGL on this group
From: earrond@calstatela.edu (Ellis Arrondo)
Date: 25 Aug 92 21:09:20 PDT
Reply-To: earrond@calstatela.edu
Distribution: world
Organization: Cal State University, Los Angeles


	Which XGL are you using XGL 1.0 or 2.0. I think if you look in the demo 
subdirectory you will find a demo that employs picking. If you can't find it let me 
know, I send you a listing.
Newsgroups: alt.3d,rec.electronics,rec.video
From: marrou@cs.ucf.edu (Lance R. Marrou)
Subject: Re: original stuff
Organization: University of Central Florida
Date: Fri, 4 Sep 1992 12:37:09 GMT

Stop with the poetry already!  Sheesh!  You think that
someone like Marcin, who apparently writes in English,
would learn how to read English!  This is alt.3d, not
alt.stupid.poetry!  Maybe if you made your poems about
3D subjects....

Is there a personal problem here, Marcin?  Are you
experiencing problems?  Try some social groups...

--
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Lance R. Marrou
   Work   - Marrou@IST.UCF.edu
   School - Marrou@Eola.cs.UCF.edu
From: lag1@RandB.CC.MsState.Edu (Ludwig "EE2B" Goon)
Newsgroups: alt.3d
Subject: NSBE
Summary: Where is the net?
Keywords: NSBE net
Date: 25 Aug 92 20:04:24 GMT
Organization: Mississippi State University

if anyone know the where about address
of the NSBE net or MIKE TUYO
drop me a line at 

lag@erc.msstate.edu
From: charles@capmkt.COM (Charles Neveu)
Newsgroups: alt.3d
Subject: TV Snow tornado (was Re: 3-D TV snow)
Date: 26 Aug 92 18:56:38 GMT
Organization: Capital Market Technology

timk@meaddata.com (Tim Klein) writes:
>An old issue of Stereo World mentions that a "stereoscopic snow storm"
>can be seen on any "empty" television channel.  "Just turn your set
>on, hold a filter before one eye, and watch the 'snow' for a few minutes.
>After a short time you observe a three-dimensional whirl of snow flakes,
>with the fast moving flakes in the periphery and the slow ones in the
>center.  [deletia]

Another interesting effect was demonstrated to me by Scott Stevenson
and Larry Cormack here at U.C. Berkeley. Get a Dove prism (a type of
prism which rotates images about the "visual" axis). Put the prism in
front of one eye and turn it so that the image in that eye is slightly
cyclorotated with respect to the image in the unaided eye. Now view a
TV snow screen and fuse the two images. A tornado-like swirl will
appear, tilted either in or out of the plane of the screen, depending
on the direction of the relative tilt of the images.

Charles Neveu
neveu@milo.berkeley.edu
Neurology Unit
UCBerkeley
Xref: sparky alt.3d:976 rec.video:10825
From: watters@darwin.genetics.washington.edu (Mike Watters)
Newsgroups: alt.3d,rec.electronics,rec.video
Subject: Re: 3DTV via LCD Glasses?
Date: 2 Sep 92 16:39:22 GMT
Article-I.D.: u.1992Sep2.163922.9665
Organization: University of Washington

In article <1992Sep2.154336.13572@samba.oit.unc.edu> Curt.Miller@bbs.oit.unc.edu (Curt Miller) writes:
>
>I was wondering if anyone has done any work with 3DTV using LCD
>shutter glasses as the medium for portraying the three dimensional
>image?  I have seen a demo of an inexpensive system by XSPECS-3D
>that used a LCD visor.  It was running on a Comodore Amiga which has 
>NTSC video output. I've also read about a system called Crystal Eyes 
>Systems put out by Stereo Graphics Corp.  (this system has a higher
>refresh rate)
>	I was wondering if anyone has done any work with either of these 
>two systems or possibly with other ones.  I would appreciate any info
>or help I can get on this project.  Thanks!
>
>	UCSKJM@UCS.UWPLATT.EDU    or  UCSKJM.UWPLATT.BITNET
>--
>   The opinions expressed are not necessarily those of the University of
>     North Carolina at Chapel Hill, the Campus Office for Information
>        Technology, or the Experimental Bulletin Board Service.
>           internet:  bbs.oit.unc.edu or 152.2.22.80

I probably won't be the only one to mention this, but over on my couch right
now is sitting a Toshiba SK-3D7K stereographic camcorder.  Has all the hardware
needed (twin lenses, CCD's etc) built right into it.  It has an interocular
of about 60mm (parallel not converged) with an ability to adjust the window
by shifting one of the lenses.

Couldn't ask for an easier, more convenient system for 3DTV.  Just point and
shoot like any other camcorder, then take it home and watch through the
LCD visor that comes with it.  Actually, the visor is my only complaint.  It's
just silly looking.   Big band that goes around your head with the shutters
stuck out on a post in the front. (does get rid of flare from the side though)

mike

--
Mike
watters@genetics.washington.edu
Dept of Genetics, Univ of Washington  Seattle
(d) 206-543-1934   (e) 206-361-1156 
Newsgroups: alt.3d
From: duane@morgan.ucs.mun.ca (Duane Starcher)
Subject: Scan formats
Organization: Memorial University of Newfoundland
Date: Wed, 26 Aug 1992 12:02:44 GMT

	This is a request for advice on graphics formats that work well
on the network.  I have scanned some colour photos in the past, but have
had variable success with them.  Using a colour scanner, what parameters
have the best chance of being viewed cleanly?  I also assume that the
files should not be so large as to upset friendly sysops.

	I would hope to learn what sizes, resolutions and numbers of colours 
work best and can be displayed full-screen without panning.  Some of my scans
also had added patterns that reduced the resolution.  Any advice will be
appreciated. 
                                                      
Duane Starcher             *             a               a      
Memorial University        S           n                n  
St. John's, Newfoundland   T               d                 d
Canada                     E         a               a   
                           R           _  _a           _   _a
                           E           0 /             0  /  
(duane@morgan.ucs.mun.ca)  O        C_/@           C_/ @ 
                           *           |               |
                                O    _/ \_        O  _/ \_
From: mzaransk@ux4.cso.uiuc.edu (Marcin B Zaranski)
Newsgroups: alt.3d
Subject: original stuff
Date: 3 Sep 92 16:30:37 GMT
Organization: University of Illinois at Urbana



soft and silent
echos
mimick the reality's
voice
promisses unfulfilled
pain and the funeral
of my desire
rain of misunderstanding,
i love moisture of
any kind

her face was a blank wall 
of deep fear
& life was in her eyes w/ hope
she smiled sadly.

	Marcin z.
Xref: sparky alt.3d:986 rec.video:10887
From: watters@mendel.genetics.washington.edu (Mike Watters)
Newsgroups: alt.3d,rec.electronics,rec.video
Subject: Re: 3DTV via LCD Glasses?
Date: 3 Sep 92 18:31:38 GMT
Article-I.D.: u.1992Sep3.183138.1137
Organization: University of Washington


There seems to bee some confusion in this group concerning the difference
between "convergence" and "window setting".  With two lenses that are
converging, the axis of the lenses cross somewhere in front of the cameras.
This leads to conflicting distortions going to the eyes and generally is
not very comfortable to view. (Much like crossing your eyes to look at an
object 5 inches from your face isn't very comfortable)

With two lenses that have their window set at some distance.  The lenses
axis are parallel.  The window is set by having the CCD (or the film) NOT
be centered behind the lenses but be offset slightly.  I have been reminded
of a good example.  Cameras designed to take pictures of buildings have
this feature.  (ie archetectural cameras and all large format cameras)
The lens axis can be shifted relative to the center of the film being
exposed.  This allows you to take a picture of a building and avoid having
the keystone distortion (makes it look like the building is falling over).

The lenses on the Toshiba camcorder ARE parallel (meaning the axis of their
lenses are parallel) however the WINDOW is set at 20ft (or whatever) by
having the CCD's not be centered behind those lenses.  The same is true
of every stereo camera ever made (with a few exceptions, namely homebuilt
units).  If you measure the distance between the lenses, and compare that
to the distance between the film openings, you will find that the lenses
are slightly closer together.

mike

--
Mike
watters@genetics.washington.edu
Dept of Genetics, Univ of Washington  Seattle
(d) 206-543-1934   (e) 206-361-1156
From: rick@tekig1.PEN.TEK.COM (Fredrick Wilson)
Newsgroups: alt.3d
Subject: Re: what to see in a picture stereogram?
Date: 26 Aug 92 21:48:52 GMT
Organization: Tektronix, Inc., Beaverton,  OR.

In article <lau.714858298@femto> lau@femto.cs.umn.edu (Patrick Lau) writes:
>What are we supposed to see in the picture stereograms? I have tried the
>usual split/corss eye methods, and all that I see is (say for the lena
>picture) six lenas on the background, and some kind of "hollow tube"
>extending outwards, with the lena pictures on the inside of the tube.
>What is so interesting about this? Or did I see the wrong thing the
>wrong way?

It looks like you are seeing the right things.  Some of us just
thought it was, well, neat.  I guess some of us didn't.
Beauty is in the (crossed) eyes of the beholder.

Think of these stereograms as a starting point.  The first random
dot stereogram was a simple square floating above a background.
That was interesting until we started seeing peoples' faces
and fractals and transparant toroids represented the same way the 
square was.  Then the square became boring.  Lena will become
boring someday to those of us who are more easily amused.
You're just way ahead of us.


      Rick   Wilson             Rick Wilson       Cross-eyed STEREO
      --------------           --------------
     |       O      |         |      O       |
     |    O         |         |     O        |    rick@sable.pen.tek.com
     |              |         |              |    Tektronix
     \    _     O   |         |\    _  O     |    Beaverton, Orygun
     |\  /      _   |         | \  /   _     |
     | \/   \  /    |         |  \/\  /      | 
      --------------           --------------      
Newsgroups: alt.3d
From: drascic@ie.utoronto.ca (SpIke)
Subject: Re: How do I generate the two views for a 3d image (LCD glasses)
Organization: University of Toronto, Department of Industrial Engineering
Date: Thu, 27 Aug 1992 16:54:53 GMT

gold@imp.sim.es.com (Bruce Gold) writes:

>In article <busey.714845002@milton>, (Thomas Busey) writes:
>|> 
>|>   My question is how to generate the left and right images for a
>|> stereo display.  Three transforms come to mind:  1) pan left and right
>|> 2) dolly the camera left or right perpendicular to "forward" 3) dolly one way 
>|> and pan the other simultaneously
>|>   I've read that local transforms of the objects such as local rotations
>|> introduce distortions such as vertical parallax.  This doesn't sound like
>|> a good solution.
>|> 
>|>   Since this is obviously still a point of active discussion, I thought
>|> I'd post to alt.3d.

>The prize is behind door number 2.  

>While eye convergence for stereoscopy does exist, its effect is a low-precision
>size queue.  It is not part of the stereoscopic effect.  That is caused by the 
>visual cortex evaluating parallex differences.

Sorry, this isn't really true.  Eye convergence is very important for near
distances, up to perhaps 2 metres or so.  The "parallax differences", known
as "disparity", is an effective depth cue up to perhaps 30 metres or beyond.

Convergence gives an absolute sense of where something is located.
Disparity gives a relative sense of whether something is closer or further
away than something else.

In any case, when creating a stereoscopic image, it is extremely important
to avoid eye-strain.  Parallel camera models, such as the one you are
suggesting, place the graphics in an area IN FRONT OF the monitor.  This is
bad for 2 reasons: first, the user spends most of her time cross-eyes, and
second, the illusion of depth is shattered near the edges of the screen.
This is because the graphics are occluded (blocked out) by the edges of the
screen, but they are supposed to be in front of it.  This clash of depth
cues (occlusion versus stereopsis) undermines your efforts.

Unfortunately, not enough programmers seem to be aware of the psychophysics
of stereoscopic displays, and wind up ignoring these issues.  This leads to
a poor display, user disatisfaction, and the rejection of what can be a very
important and useful display technique.

>Since you are interested in doing psychology research, you will surely be 
>interested in what aspects of the stereo effect are already known to be
>contributed by projective geometry, the physiology of the human visual system,
>and psychological phenomena already discovered.  It's easy and rewarding to
>get started in your survey of the literature.

Well, it may be easy to start, but keeping it up and doing it in depth is a
real killer! :-)

One good place to start is with the SPIE Stereoscopic Displays and
Applications conference proceedings.  There have been 3 meetings so far, and
the proceedings (available at many university libraries) are chock full of
the latest research.

	David Drascic
	Dept of Industrial Engineering
	University of Toronto
	drascic@ie.utoronto.ca
From: halazar@media.mit.edu (Michael Halle)
Newsgroups: alt.3d
Subject: Re: How do I generate the two views for a 3d image (LCD glasses)
Date: 29 Aug 92 23:38:07 GMT
	<BtpExz.4t3@ie.utoronto.ca> <6777@tekig7.PEN.TEK.COM
	<BtrBBI.6pF@ie.utoronto.ca>
Organization: M.I.T. Media Laboratory


"stereo window" is a term used to describe the plane of space where
the viewing frusta of the two stereo taking cameras overlap.  The term
can also be applied analogously to the stereo projection geometry.
For non-shifted, parallel-axis camera, the stereo window is located at
infinity.

The terms of stereography are historically vague and ambiguous, so it
is very difficult to use terms in a way that will mean the same thing to
everybody without constantly having to define them.

						--Michael Halle
						Spatial Imaging Group
						MIT Media Lab
Newsgroups: alt.3d
From: tfrey@rp.CSIRO.AU (Thierry Frey)
Subject: Where ?
Organization: CSIRO Division of Radiophysics/Australia Telescope National Facility
Date: Thu, 27 Aug 1992 06:58:26 GMT

I heard someone has loaded some random dots stereograms at an ftp site, as
postscript files. Could that person ( or someone else !) please give me
the adress of the ftp site.

Thanks in advance,

	Thierry
Newsgroups: alt.3d