StereoVU Version 1.3 May 1997 By Shane McKee

====================
What is StereoVU?
====================
StereoVU is an application for the Psion Series 3a palmtop, allowing
you, the user, to view stereograms (3D images), as well as create
your own stereogram files. Use your artistic talents in three
dimensions!

It's streets ahead of any other similar program I've come across, in
that it allows you to create and view complex images, as opposed to
simple shapes. The program is currently available as FreeWare.

====================
The Distribution Files
====================
StereoVU is distributed as the following file bundle:

STEREOVU.OPA
STERVU.TXT (this file)
STERED.ALS (an alias Text Editor file for making .STGs)

*PLUS* several Stereogram files (.STG), demonstrating the principle
of creating your own stereograms.

You may freely distribute these files, place them on bulletin boards,
FTP sites, your homepage, etc, as long as you include the ZIPped
distribution file: STERVU13.ZIP as a bundle. Do not break up the
family.

====================
Installing StereoVU
====================
You need a Psion 3a (somebody please let me know if this works on a
3c!), with at least 16K of disk space. When running, the program needs
an additional 44K of system resources. Not much.

To install, simply UNZIP, and place STEREOVU.OPA in an \APP
directory, then install from the system screen. (Press Psion-I, and
select STEREOVU.OPA). The file will install, and you can run it in
the normal way. Put STERVU.TXT in your preferred text directory
(optional), and the .STG files in the \OPD directory. Then simply run
the program from the system screen.

ALSO: If you're the artistic type, and you wish to create your own 
stereograms, put STERED.ALS in the \APP directory, and install 
from the system screen. Details on how to create your own stereograms 
are given later.

On startup the program will create a Background image to map onto the
stereogram template. It will then generate the default stereogram.
This takes about 30s. Press MENU at any time during or after
generation to select options.

====================
What is a Stereogram?
====================
Stereograms are a form of optical illusion, which trick the brain into perceiving a 3
dimensional image from a 2 dimensional one. Well, that's actually
slightly misleading - there are in fact two images - one for the left
eye and one for the right - but they're cunningly interwoven into
one. Subtle differences between the two images allow the brain to
appreciate depth, thereby rendering the 3D effect. The really cunning
part is in the combination of the two images into one, and the effect
is appreciated by viewing the image in a special way.

====================
How do I view a Stereogram?
====================
You may already know how to do this from the books and posters that
are widely available (recognised Tradenames are "Magic Eye (R)" and
"5D (R)"). What you need to do to view StereoVU stereograms is:

	1:	Display the image on the Psion screen
	2:	Hold the Psion about a foot away from you
	3:	Make sure you have good lighting!
	4:	Let your eyes go out of focus

Now, if you do that, you will see a blurry Psion in double-vision.
The stereogram image will overlap with itself. You'll also see the
button-bar buttons overlapping. Now you need to let your eyes refocus
on the image, while maintaining a single overlap. (Sounds easy,
doesn't it?)

You'll have noticed that the screen image looks like a mess of
letters, but that the image consists of several repeats across the
screen. The trick, of course, is to get one repeat unit (as seen by
the left eye) to overlap onto an adjacent repeat unit (as seen by the
right eye). Actually, that's the easy bit - it's getting your eyes 
to refocus that's difficult.
Try the following tips:

	1:	Narrow your eyes
	2:	Move the Psion slowly away from you
	3:	RELAX, and let your eyes adjust

Take your time - it took me several weeks to be able to see them
properly. But persevere! It might help to print the screen, and view
it from paper (at least until you get the knack). Some of your
friends may infuriate you by being able to see the image more
quickly. Don't be put off. This will NOT damage your sight,
and you SHOULD get there eventually.

====================
What's in the Program?
====================
The full (STEREOVU.OPA) program allows you to:
        1/:     View Stereograms 
	2/:	Load your own stereogram files
        3/:     Change the background 
	4/:	Save the output as a .PIC file
        5/:     Load inbuilt stereograms 
        6/:     Enter text to be rendered in 3D 
        7/:     See what the stereogram SHOULD look like
        8/:     Utterly amaze your entire social circle 

====================
OK - a quick run-through?
====================
Start up the program. Wait while the background & stereogram are
generated. Then hit MENU.

Select "Show stereogram: Psion-W" from the Display menu. This will
show you what you are looking for. Then press a key.

If you find it hard to see, try changing the background settings
(from the Settings menu). If you're still having problems with the
background, you can load in a .PIC file to map over the stereogram.
Go to "Settings" -> "Change" -> "Background: Load .PIC File". That
should do the trick (provided you have a .PIC file in the first
place!)

Try pressing Psion-T to enter 5 characters of text. These will then
be rendered as a stereogram before your eyes!

Psion-L allows you to load your own stereogram template files (see
later for how to create template files).

Psion-I allows you to load one of several inbuilt stereograms for
viewing.

HELP or Psion-A should give you some more hints.

Play about with it, and if you come across any bugs, please let me
know.

====================
How do I create Stereogram Template Files?
====================
It's really easy. You just use a text editor to create the image. 
Install STEREOED.ALS from the system screen. This provides
you with a text editor, using files with extension .STG, in the
\OPD directory.

Then open up a file, and - THIS IS IMPORTANT!!! - put in the first
line: "Stereogram Template File" - EXACTLY as you see it here -
spaces & all - (leave out the quotes). See the example files to show
you how it's done. This simple measure prevents you inadvertently
loading a bogus file. Remember .STG files should be in TEXT, not WRD
format. If you use StereoEd.ALS, this will not be a problem.

You now have access to an 80-by-32 grid of "pixels". Each pixel 
can be set as "Background", "Plane 1", or "Plane 2". Plane 2 is 
the highest (nearest, when viewed in 3D). A pixel is assigned 
to a plane by entering a " "(space) for BACKGROUND, "1" for 
PLANE-1, and "2" for PLANE-2. Again, see how it's done in the 
example files. Remember NOT to use any other characters
than space, "1" & "2" in the body of the file. Any text after the
33rd line is ignored.

Example:
-------------------------
Stereogram Template File

     111111111111
     111122221111
     111122221111
     111111111111

-------------------------

will show a small rectangle floating above a larger rectangle.

Load the completed file up in the program, and view as normal. If you
develop any great stereograms, let me know, and I might include them
in the next bundle!

Feel free to convert the .PIC files for use on your web pages as you
see fit - but please make a link to:

        http://www.infosites.net/dnet/dnethWMo/psion1.htm

and credit me with the program. Thanks!

Also, for other examples of stereograms, see the above URL.

====================
How do I register STEREOVU?
====================
You don't.

====================
Comments, Bugs, Suggestions, etc
====================
I welcome any suggestions on how to improve this program. Please
email me:
	shane@mckee.dnet.co.uk

Alternatively, drop in on my guestbook at:

        http://www.infosites.net/dnet/dnethWMo

I look forward to hearing from you!

====================
Legal stuff
====================
I have tried this program out in many different scenarios, without
any loss or corruption of data, and therefore don't think it has any
major problems. HOWEVER, I cannot be legally or morally held
responsible in any way for any adverse events arising from the use of
this software, including, but not limited to, hardware or software
damage, personal injury, social problems, global warming, 
unemployment, nuclear war. I retain full copyright of 
the program & associated files.

====================
History
====================
Ver 1.0: January 1997. Slow. Left gaps in complex pictures

Ver 1.1: Feb-Mar 1997. First release. Pictures complete, but
         still slow. Bug in file opening. Added text conversion &
         "Give-away" rendering of stereograms.

Ver 1.2: Mar-Apr 1997. Re-release. Faster stereogram algorithm.
         File-opening bug fixed.

Ver 1.3: May 1997. StereoVu goes FREEWARE!
         HELP Bug removed.

For the future (watch my web page!):
	Dedicated stereogram editor program.
	More compact file structure.
	Possible algorithm improvements.
	More example files (keep sending them in!).

====================

-Shane McKee, May 1997

shane@mckee.dnet.co.uk

