Stereogram FAQ
General Questions
[1] What is a SIRDS/Stereogram/Hollusion/SIS?
[2] Terminology
[3] How do I see them? Everyone else can see them....
[4] Where can I buy the posters from?
[5] How can I generate them myself?
[6] Which books/papers should I read?
[7] What is a SIRTS/Ascii-Stereogram
[8] Where is most of the discussion about SIRDS?
[9] Internet locations for material (lots of pictures!)
[10] Stereogram History
Subject: [1] What is a SIRDS / Stereogram / Hollusion / SIS?
Have you walked through a mall lately? These days, as you wander past
most of the poster shops, there will be a large group of people
staring at the same poster with surprisingly weird expressions on
their faces. Some will be in the initial stages of denial or
rejection---they will be concentrating, some slowly rocking their
heads backwards and forwards, searching for an image that they have
never seen before. Others will be grinning from ear to ear, pointing
at the poster, chuckling with their friends that a member of their
group hasn't seem them yet. "Come on Bill, come on!", they cry and as
Bill gets increasingly more frustrated he concentrates harder and
harder, until finally (if he's lucky) he sees a true 3D image,
without the need for special glasses or equipment.
These pictures are known as Single Image Random Dot Stereograms
(SIRDS), or Single Image Stereograms (SIS) depending on whether the
picture contains random dots as a base for the 3D effect, or a
repetitive pattern. Unfortunately, each commercial company has
labelled them differently. Shop owners generally don't know what you
mean, unless you say "Hollusion" or one of the many other specific
names.
Stereogram Mechanism
-- Cristian Alb (luminita@poincare.mathappl.polymtl.ca)
Disclaimer:
All the opinions and ideas presented in this [article] are
mine and are the result of my own reflections on the subject.
Purpose:
This document wants to provide an easy understanding of the mechanism
of 3-D perception related to stereograms. Due to the fact that it is the
result of genuine thinking, I hope that this document provides a more
intuitive approach to the subject.
What is a stereogram ?
In this document I refer to stereogram (though, single image stereogram
would be more correct) as being something like the image that follows:
/=-- Y+-z-/=-- Y+-z-/=-- Y+-z-/=-- Y+-z-/=-- Y+-z-/=-- Y+-z-/=-- Y+-z-/=-- Y+-z
*wm @m@w *wm @m@w *wm @m@w *wm @m@w *wm @m@w *wm @m@w *wm @m@w *wm @m@
O@=*+z @:/O@=*+z @:/O@=*+z @:/O@=*+z @:/O@=*+z @:/O@=*+z @:/O@=*+z @:/O@=*+z @:
:*/- :m: *:*/- :m: *:*/- :m: *:*/- :m: *:*/- :m: *:*/- :m: *:*/- :m: *:*/- :m:
)*/O@-Y|- )*/O@-Y)*/O@-Y)*/O@-Y)*/O@zO@)*/O@z zO@)*/O@zO@)*/O O@zO@*/O O@zwO@*/
*):O*zO((@*):O*zO*):O*zO*):O*zO*):O*mO*z):O*mO(O*z):O*(O*z):+:O*(O*):+:O*()O*):
m))@z@-+m~m))@z@-m))@z@-m))@z@-m))@z*@z@-m@z*@z@@@-m*@z@@@m@-m*@z@@m@-m*@z @@m@
z:+*O-mm*Yz:+*O-mz:+*O-=O-mz:+*O-=O-mz:+*O--mz:+***-mz:+*)***-mz:+****-mz:-+***
m@: @:~+( m@: @:~m@: @: @:~m@: @: @:~m@: @: @m@: @: @m@/@: @: @m@/@ @: @m@+/@ @
-+(*m- o-)-+(*m- -+(*m-Om- -+(*m-Om- -+(*m-Om-+(*m-Om-+-+(*m-Om-+-+*m-Om-+|-+*m
m*m |== *m*m |=m*m |=m*m |=m*m |=m*m |=m*m*m |=m*m*m |=m*m+*m
+ YY/ + ) + YY/ ++ YY/ ++ YY/*Y/ ++ YY/*Y/ ++ Y*Y/ ++-+ Y*Y/ ++-+ YY/ ++-+* YY/
zY=) w ~/YzY=) w zY=) w zY=) z) w zY=) z) w zY=z) w zmzY=z) w zmzY=) w zmz|Y=)
+ oY*:+:ow+ oY*:++ oY*:m*:++ oY*:m*:++ oY*:m*:+oY*:m* *:+oY*:m* *:+Y*:m* *z:+Y*
@ z++ *zo)@ z++ *@ z++ w+ *@ z++ w+ *@ z++ w+ *z++ w+ + *z++ w+ + *++ w+ +* *++
()=ww+ *O()=ww+ ()=ww+-w+ ()=ww+-w+ ()=ww+-w+ =ww+-w+w+ =ww+-w+w+ ww+-w+w=+ ww
z +wO z +z + +z + +z + + + = + + = + + = ( +
o +@~@= ozo +@~@=o +@~@+~@=o +@~@+~@=o +@~@+~@=+@~@+~@~@=+@~@+~@~@=@~@+~@~z@=@~
)(w=++ +~z)(w=++ +~z)(w=++ +~z)(w=++ +~z)(w=++ +~z)(w=++ +~z)(w=++ +~z)(w=++ +~
mz- O @ =mz- O @ =mz- O @ =mz- O @ =mz- O @ =mz- O @ =mz- O @ =mz- O @
If you stare at this image by trying to focus on something behind the
image, you will be able to see, after some-time, a 3-D scene with the
letters F Y I detaching from the background. (If you read this document
on a monitor it is easier to focus on your image reflected on the screen
in order to get the 3-D illusion. If you read this document on paper,
try to put a glass in front of it and do the same thing.)
To understand the mechanism which allows you to get this
peculiar effect, we should take a look at the process of vision.
The feeling of "depth" that you get by looking at a statue instead
of looking at a photo of the same statue, is due to the fact that
the human body has two eyes.
In the above example with the statue, we need just one eye to get
the general shape of the statue. A humble photo does the same. It is
the second eye that provides some "extra" information. This extra
information is the "depth" of the various parts of the statue.
In fact a "photo" gives just a bi-dimensional (x,y) representation,
to get the third dimension (z) you need some "extra".
y
| |---------
| z | Photo |
| / | |
| / ---------|
|/_______ x
By having two pictures of the same object, taken by two different positions,
which is the case of the human eyes, you can get the "z" coordinate to
that object. It is a simple geometrical question.
In fig.1 we assume that there are 2 objects, X and Y which are at the same
height (y) and different depths (z) and positions (x)
|------------------------------------------------------------|
| Fig.1 |
| z |
| y | |
| Y \ | |
| \|_____x |
| |
| |
| |
| |
| |
| X ^ |
| | |
| | |
| | |
| (o) (o) |
| watching |
| left-eye right-eye direction |
| (depth) |
|------------------------------------------------------------|
In fig.2 are shown the kind of "pictures" that each eye gets:
(fig.2L -left eye, fig.2R -right eye; the '+' marks the center of each picture)
|------------------------------| |-----------------------------|
| Fig.2L | | Fig.2R |
| | | |
| | | |
| | | |
| X Y + | | X Y + |
| | | |
| | | |
| | | |
| | | |
|------------------------------| |-----------------------------|
As you can notice the 'X' shifts more than the 'Y' from one picture to
another. This is an indication that the X object is 'closer' than Y.
- shift.X = d.hrz.right ( X, '+') - d.hrz.left ( X, '+')
- shift.Y = d.hrz.right ( Y, '+') - d.hrz.left ( Y, '+')
where "dx.hrz.hhh ( A, '+')" means distance (on the horizontal axis)
in the hhh picture from object A to origin/center.
Furthermore, with good approximation we can say that any objects with the
same 'shift' are at the same "depth" (z)
In the same way, the eyes forward to the brain two slightly different
pictures. It is the brain that must "compute" a 3-D representation of
the scene.
The difficulty is to know which pairs must be associated to "compute"
the z-coordinate. In the example above it's easy to assume that the
'X' from each picture is associated to one 'X' object. The same goes
for the two 'Y'. But the images that the brain gets to compute, can be
quite complicated. What if there are more X-s and Y-s in each picture ?
How does the brain establish the "couples" for which to calculate the
shift/depth ? A clue is that each pair must be on the same height (y).
Which means that the brain should not try to associate spots, patterns
that are located at different heights. But that is not enough !
The 'brain' can make mistakes in this process of designation of
pairs!
It is that which make possible the 3-D feeling that we get from
stereograms.
The simplest stereogram that we can get is something like-this:
_______________________________________________________________
| * * * * * * |
| * * * * * * |
| * * * * * * |
| * * * * * * |
| * * * * * * |
| * * * * * * |
| * * * * * * |
| * * * * * * |
| * * * * * * |
| * * * * * * |
| * * * * * * |
| * * * * * * |
| * * * * * * |
| * * * * * * |
| * * * * * * |
| * * * * * * |
| * * * * * * |
| * * * * * * |
|-------------------------------------------------------------|
Column:1 2 3 4 5 6
Using the same procedure as in the beginning of this document you should be
able to see the same '*' columns but "somewhere behind" this document.
In fig.3 (Left/Right) I have represented the kind of pictures that the eyes
forward to the brain when looking at the preceding stereogram.
(notice '+', the center)
|-------------------------------| |-----------------------------|
| : : : : :Fig.3L | |: : : : : Fig.3R |
| : : : : : : | |: : : : : : |
| : : : : : : | |: : : : : : |
| : : : : : : | |: : : : : : |
| : : +: : : : | |: : : : + : |
| : : : : : : | |: : : : : : |
| : : : : : : | |: : : : : : |
| : : : : : : | |: : : : : : |
| : : : : : : | |: : : : : : |
|-------------------------------| |-----------------------------|
column:
1L 2L 3L 4L 5L 6L 1R 2R 3R 4R 5R 6R
Normally the brain will associate the columns in the following way:
- 1L-1R, 2L-2R, 3L-3R, 4L-4R, 5L-5R, 6L-6R
but it can happen that the brain does the following association:
- 1L-2R, 2L-3R, 3L-4R, 4L-5R, 5L-6R, ?-1R, 6L-?
Remember: All columns look alike !
Of course it is possible that the brain makes other associations of these
kinds:
- 1L-3R, 2L-4R, 3L-5R,... or 2L-1R, 3L-2R, 4L-3R,... etc.
but in these cases the resulting 3-D representations makes no sense, or
are very little alike.
It can be noticed that by choosing a diferent association of columns
the "shift" between the images of the objects changes. As a result
the "depth" of the perceived objects changes. In the association 1L-2R,
2L-3R,... the shift is reduced -> the "depth" increases -> the columns
seem somewhere behind.
Is it possible to determine exactly the power of the brain
in matching complicated images ?
I thought, some time ago, what would happen if we put someone in front
of a large panel situated at a convenient distance (so that the eyes
are relaxed) and the panel is full of randomly disposed spots.
The spots should be all alike and in very great number, very small
but big enough to not became a uniform gray. The brain
should be overwhelmed by the great number of matches that it must
try. What will happen ? The person will get dizzy ? get a headache ?
Or will the person be forced to see just a gray fog ?
Subject: [2] Terminology
- Different types of images:
- Autostereogram: Original name for a SIRDS
- RDS: Random Dot Stereogram
- SIRDS: Single Image Random Dot Stereogram
- SIRTS: Single Image Random TEXT Stereogram
(also known as ascii stereograms)
- Stereogram: This is a general, simplified term for SIRDS
and SIRTS (occasionally stereo-pairs)
- Different viewing actions:
- Wall-eyed: Converging eyes past the actual image
- Cross-eyed: Converging in front of the image
- Infinity-focus: Forcing your eyes' lines of sight to be parallel
(not necessary for wall-eyeing SIRDS)
Subject: [3] How do I see them?
Most Stereogram pictures are usually generated so that if you look at
(converge your eyes on) a position twice as far away as the picture,
and focus on the picture, generally after a few minutes you see a
surprising 3D image!
Most people find this extremely difficult for the first time. You
have to focus on a point which is different from where you are
looking. This is known as "de-coupling" your vision process.
Instinctively people focus at the same point they are looking at, and
this is the main obstacle in seeing images of this type.
This is why most posters come with a reflective surface such as glass
or plastic covering them---if you try to look at your reflection you
will be looking at a point twice as far away as the actual poster. It
has been noted by almost everyone that while this sometimes helps
beginners see the 3D effect for the first (and perhaps even the first
few) times, experienced viewers to not need any help like this, and
indeed the reflection is usually very distracting and decreases the
quality of the 3D effect.
There are many ways to teach this de-coupling to either yourself or
to others, including (in almost no particular order):
NOTE: It is generally easier to see Stereograms under bright light. I
have been told this is because you eye relies less on focus under
harsh conditions. Another point, to see stereo images, you need to
have "passable" use of both eyes. If you wear glasses try with and
without them on. Some short-sighted people can see them easier
without their glasses on (if they get closer to the picture).
The pull-back
Hold the picture (or move your face) so your nose is touching the
picture. Most people than can not possibly focus with something this
close to their eyes, and they will be content with their inability to
focus. With the picture up close, pretend that you are looking
straight ahead, right through it. Now slowly pull the picture (or
your face) away while keeping your eyes pointed straight ahead. If
you do this slow enough, an image usually appears when the picture is
at the correct distance.
The reflection
As mentioned above, with a reflective surface it is sometimes a lot
easier to converge your eyes in the correct position. You simply
focus on your nose or some central reflection in the picture, and wait
until you focus on the image.
The drunk-eyes
This method is used to describe the feeling of the process of
deconverging your eyes. It is very much like being drunk or having
"staring-eyes". Your eyes don't look at the object, but rather
through it. This state is common to some in the morning before the
coffee caffine fix.
The wall, or the finger
Hold the picture so that it is half between you and a wall. Look
*over* the top of the picture towards the wall, and focus on something
such as a picture hook or mark. While keeping this "gaze" either
slowly lift the picture or lower your eyes while keeping them
converged on the wall.
A similar approach (but for cross-eyed viewing) is to stand arm's
length away from the picture and put your finger on the picture. While
slowly pulling your finger towards your face, keep looking at your
finger, you will notice the picture becoming blurry, and at an
intermediate position you will (eventually) see the 3D image.
The see-through
Photocopy the picture onto a transparency. Then
focus through the transparency onto something twice as far away. This
is similar to (The wall, or the finger) above except now you don't need to change the
position of your gaze.
Wide-Eyes
This method involves building a device to widen your interocular
distance, as well as allowing the adjustment of the convergence of
your eyes. It's so simple, you almost don't have to be there!. I have
had a look through such a device, and the results were very good.
(diagram pending...)
Cheating...
To cheat, photocopy the image onto two transparencies, then overlay
them and carefully shift them horizontally so they are about an inch
or two out of alignment. Somewhere around this position you will see
a rendition of the image. Obviously in 2D not 3D, but you will at
last finally believe there is "somethere in there."
And if you're still having difficulty, this comment by jhakkine@cc.Helsinki.FI (Jukka Hakkine),
may apply to you:
"Richards (1970; Experimental Brain Research 10, 380-388) did a
survey among 150 MIT students and noticed that "...about 4%
of the students are unable to use the cue offered by disparity, and
another 10% have great difficulty and incorrectly report the depth
of a Julesz figure relative to background." He further concludes that
inability to use stereopsis is an inherited defect and is related
to "three-pool"-hypothesis of binocular neurons."
But don't dispair, don't give up until you're tried for at least a month!
Subject: [4] Where can I buy the posters from?
For those who do not have a local SIRDS distributor (i.e., the poster
cart at the mall), here are a few companies you may be able to order from.
------------- Infix Technologies -------------
$20 Earth (mercator projection of the Earth's altitudes)
$20 Salt Lake LDS Temple Centennial
$20 Beethoven (300 DPI! Very smooth.)
These prints are 18x24 inches.
Retail price for the 18x24 inch prints is $20 plus $3 s/h. Utah
residents add 6.25% sales tax. Wholesale and distributor discounts
are available. Quotes for custom work are also available. Cost and
minimum order varies, based on content.
PO Box 381
Orem, UT 84057-0381,USA
Ph: (801) 221-9233
email: John M. Olsen (jolsen@nyx.cs.du.edu)
------------- Inner Dynamics, Inc. -------------
(Distributors)
Privileged Traveler
4914 Brook Road
Lancaster, OH 43130, USA
(614) 756-7406
Glow in the Dark Poster Series - $22 (size: 18" X 24")
-
"Knight Vision" - suspended chess board with chess pieces above the board
in daylight viewing; also an area in the center that has
a Knight chess piece; random dot pattern glows and is
viewable in the dark!!
Premium Color Series - $16 (size: 18" X 24")
- "Gecko" - twin Gecko lizards
- "I Think Therefore I Am" - well known quote surrounded by stunning visuals
- "SoulMate" - hearts, spirals, and other symbols, for that special person
- "The Mighty Unicorn" - unicorn, mystical castle, wizard, and flying dragon
- "Excalibur" - legendary sword in the stone, castle, knights, etc.
- "Where's Wilbur?" - can you find him in the forest?
Optimum Series - $15 (size: 24" X 36") (black and white)
- "Beyond Reality" - hearts, spirals, other cool shapes; extremely detailed
- "20/20 Third Sight" - an eye chart done in 3D
- "Illusions" - a labyrinth, try to find your way out!
- "Meditation" - contains an ancient mandala, a real stress buster
- "DreamWeaver" - unusual geometric shapes, `helps' induce lucid dreaming and
dream remembrance
- "Icons" - the five symbols of life; very stunning visuals
- "Rainbows" - see color on a black and white poster (Not a 3D poster)
Retail prices (USA) stated above plus $3 S&H (USA) - call for overseas S&H.
Ohio residents add 5.5% sales tax.
------------- Altered States -------------
92 Turnmill St,
Farringdon,
London, EC1, U.K.
+44 (0)71 490 2342
Paul Dale (P.A.Dale@bath.ac.uk)
tel: +44 (0)225 826 215
------------- N.E. Thing Enterprises -------------
Send a catolog request to:
N.E. Thing Enterprises
19C Crosby Drive
Bedford, MA 01730, USA.
-- info from: Neal T. Leverenz (at802@yfn.ysu.edu)
Subject: [5] How can I generate them myself?
There are many fine programs for generating SIRDS out there in the
Internet. The following programs are available from
ftp://katz.anu.edu.au/pub/stereograms(IP 150.203.7.91).
Here is a list of the ones I currently know about:
- Acorn
- mindimg
- PC
- 3DRANDOT
- ANIM - 3D animation, in 3D
- DYNAMIC
- HIDIMG - SIS as well as SIRDS. You can use a pattern, save BMP files
- MINDIMG - Stereopairs (red/blue, red/green) as well as SIRDS
- PERSPECT
- RDSDRAW
- SHIMMER - making it easier to see SIRDS
- SIRDSANI
- SIRDSVU11
- VUIMG340
- Mac
- random-dot-autostereograms
- Unix/X
- xpgs - 3D objects
- rle2pgm - converts the popular MINDIMG format to PGM
- RaySIS - SIS raytracer
Subject: [6] Which books/papers should I read?
Books
"Stereogram"
(c) 1994, Cadence Books, P.O. Box 77010, San Francisco, CA 94107, USA.
A newly edited version of CG STEREOGRAM and CG STEREOGRAM 2,
published by Shogakukan Inc. In Tokyo, Japan"
ISBN 0-929279-85-9
US$ 12.95
I liked it. Much better in my opinion than the other Stereogram
book I've seen ("Magic Eye"). This one includes much textual
information, including the origins of stereograms, how to see them,
precursors such as stereo pairs, and an article by Christopher W.
Tyler, who invented the SIRDS.
Best of all were the stereograms themselves. There are roughly
50 SIRDS, most of them full page (the book is softcover and about 8"
square). The ones I've managed to see so far have been quite good,
and also included are some of the very first ones. In the history
department there are stereo pairs, stereo photographs, and even some
stereo-pair paintings by Salvador Dali.
All of the stereograms indicate whether they require wall-eyed or
cross-eyed viewing (or either). Most are true 3d designs, not the
"cutout" variety.
The book is 93 pages and most of the plates are full-color.
Well worth the money in my opinion.
-- Michael Moncur (mgm@xmission.com)
I highly recommend the new book "Stereogram" by Cadence books, ISBN
#0-929279-85-9 (in Canada). It is a fantastic book that includes hundreds
of stereograms, stereo pictures, RDS's, lots of very interesting writeups
on the history of stereograms, a cool section on Salvador Dali (stereo
pair aritst). The concentration of course is on the pictures. The book is
just under 100 pages.
Much better value then Magic Eye. It's even got some cool cross-eyed only
viewing stereograms, which I'd never seen before this (I'd always used the
other technique).
If you have *any* interest in stereograms, buy this book, you won't regret
it!! At $17 Cdn, it's not that much either, considering the amount of time
you'll spend revelling in the 3d inside.
-- Ian Sewell (3386005@queensu.ca)
"Principles of Cyclopean Perception"
(c) 1972 by Bela Julesz,
MIT press.
Considered by most as the original work oPn Random Dot Stereograms:
-- Charles Eicher (CEicher@Halcyon.com)
"Magic Eye: A New Way of Looking at the World"
(c) 1993 by N.E. Thing Enterprises.
Andrews and McMeel, A Universal Press Syndicate Company
Kansas City, USA. ISBN: 0-8362-7006-1
First Printing, September 1993 ... Fifth Printing, January 1994
Introduction contains a history of the technique and phenomena.
Viewing Techniques are explained. 25 pages of full-color STARE-E-O images.
(Plus images inside the front and back covers.) "Answers" included.
32 pages, hardcover, 8.75x11.5 inches, horizontal format, with slipcover.
US$12.95 ($16.95/Canada)
"Magic Eye II: Three Dimension Trip Vision"
(c) 1992 by N.E. Thing Enterprises/Tenyo Co., Ltd.
Korean Translation (c) 1993 by Chungrim Publishing Co.
All the text is in Korean, so I can't read it. But it has some pretty
cool pictures. They are all SIRxS where x is various patterns/pictures.
I paid US$20 for it. Interestingly, this title doesn't seem to be mentioned
in my N.E. Thing catalog.
-- Mark Hudson (M_Hudson@delphi.com)
They've taken the technique a step further by applying the pseudo-random
patterns as noise superimposed over another image. You look at the pages of
this book and see one image, then cross your eyes and concentrate on the
replicated patterns in the background noise and see the second image. It's
kinda cute.
-- Robert Reed <robert@slipknot.rain.com>
"Das magische Auge" (German version of "Magic Eye")
(c) 1994, arsEdition, Munich
ISBN 3-7607-8297-3
DM 29,- (seen at a store for this price)
"Stereo Computer Graphics and Other True 3D Technologies"
(c) 1993, David F. McAllister, Ed.
Princeton University Press
ISBN 0-691-08741-5 US$75.00
It has several nice color plates, with stereo "triads". The triads consist
of a left, a right, then another left image. Use the left pair for viewing
walleyed, or the right pair for viewing crosseyed.
-- Mike Weiblen (mew@digex.net)
"Random Dot Stereograms"
(c) 1993, Kinsman Physics, P.O. Box 22682, Rochester, NY 14692-2682, USA.
An excellent source of information (sample RDS and source code)
-- Eric Thompson (E.Thompson@ncl.ac.uk)
ISBN 0-9630142-1-8
US$ 13.95
"Human Stereopsis. A psychological Analysis"
(c) 1976, W.L. Gulick and R.B. Lawson,
Oxford University Press.
Papers
B. Julesz and J.E. Miller, (1962)
"Automatic stereoscopic presentation of functions of two
variables"
Bell System Technical Journal, 41: 663-676; March.
R.I. Land and I.E. Sutherland, (1969)
"Realtime, color, stereo, computer displays"
Applied Optics, 8(3): 721-723; March
D. Marr and T. Poggio, (1976)
"Cooperative computation of stereo displarity"
Science, 194: 283-287; October 15
D. Marr and T. Poggio, (1979)
"A computational theory of human stereo vision"
Proceedings Royal Society of London, B204: 304-328
Science, 194: 283-287; October 15
G.S. Slinker and R.P. Burton, (1992)
Journal of Imaging Science and Technology,
36(3): 260-267; May/June
D. G. Stork and C. Rocca, (1989)
"Software for generating auto-random-dot stereograms",
Behavior Research Methods, Instruments, and Computers
21(5): 525-534.
H.W. Thimbleby and C. Neesham, (1993)
"How to play tricks with dots"
New Scientist, 140(1894): 26-29; October 9
H.W. Thimbleby, S.J. Inglis, and I.H. Witten, (1994)
ftp://ftp.cs.waikato.ac.nz/pub/SIRDS (IP 130.217.240.3), in press.
C.W. Tyler and M.B. Clarke, (1990)
"The Autostereogram"
SPIE Stereoscopic Displays and Applications
1258: 182-196
C. Wheatstone, (1838)
"Contributions to the physiology of vision. Park I. On
some remarkable, and hitherto unobserved, phenomena of
binocular vision"
Royal Society of London Philosophical Transactions
128: 371-394
C. Wheatstone, (1838)
"Contributions to the physiology of vision. Park II. On
some remarkable, and hitherto unobserved, phenomena of
binocular vision (continued)"
The London, Edinburgh, and Dublin Philisophical Magazine and
Journal of Science, series 4, 3: 504-523
Subject: [7] SIRTS/Ascii Stereograms
For people without graphics displays, or simply like having
a 3D .signature, you can create a stereo effect using repetitive
characters.
Text Stereograms (not random)
-- the following by Dave Thomas (dthomas@bbx.basis.com)
O O
n n n n n n n n n n n n n n n n
f f f f f f f f f f f f f
e e e e e e e e e e e e e e e e
a a a a a a a a a a a a a
a a a a a a a a a a a a a a a a
r r r r r r r r r r r r r
r r r r r r r r r r r r r r r r
g g g g g g g g g g g g g g g g g g g g
r r r r r r r r r r r r r r r
e e e e e e e e e e e e
a a a a a a a a a a
t t t t t t t t t
]]][[[[]]]][[[[]]]][[[[]]]][[[[]]]][[[[]]]][[[[]]]][[[[]]]][[
d d d d d d d d d
e e e e e e e e e e
p p p p p p p p p p p p
t t t t t t t t t t t t t t t
h h h h h h h h h h h h h h h h h h h h
-- the next few are by DR J (me90drj@brunel.ac.uk)
Look for his new upcoming Text Stereogram Guide---out soon!
/^\ /^\ /^\ /^\ /^\
####################################################################
####################################################################
_/ #### _/ ####\ _/ #### \ _/ #### \ _/#### \
/ ## \__/ ## \__/ ## \__/ ## \__/ ## \
____ ## ____ ## ____ ## ____ ## ____ ## ____
/ \## / \ ## / \ ## / \ ## / \ ##/ \
| 2D |# | 2D |## | 2D | ## | 2D | ##| 2D | #| 2D |
| or |# | or |## | or | ## | or | ##| or | #| or |
| 3D |# | 3D |## | 3D | ## | 3D | ##| 3D | #| 3D |
| ?? |# | ?? |## | ?? | ## | ?? | ##| ?? | #| ?? |
| | | | | | | | | | | |
-------- -------- -------- -------- -------- --------
\\\\\\\\ \\\\\\\\ \\\\\\\\ \\\\\\\\ \\\\\\\\ \\\\\\\\
\\\\\\\\ \\\\\\\\ \\\\\\\\ \\\\\\\\ \\\\\\\\ \\\\\\\\
\\\\\\ \\\\\\ \\\\\\ \\\\\\ \\\\\\ \\\\\\
/^\ /^\ /^\ /^\
_ / \ _ / \ _ / \ _ / \ _
/ \_ \_ / \_/ \_ / \_ / \_ / \_ / \_ / \_
/ \ \ / \ \ / \ \ / \ / \
__/ \ __/ \ __/ \ __/ \ __/ \
xx \ /xx \ xx \ \ xx / \ xx / \ xx
x XX x \_ x XX \ x x XX \ x x XX \ x x XX _/ \ x XX
X XX-x-x-XxX--X XX-x--x-XxX-X XX-x---x-XxXX XX-x----x-XxX XX-x-----x- X XX
XxXX X XxX XxXX X XxX XxXX X XxX XxXX X XxX XxXX X Xx XxXX
XXxX __X XXxX __X XXxX __X XXxX __X XXxX __ XX
XX XX XX XX XX XX
__XX ______XX ______XX ______XX ______XX ______XX
(Cactii modified from a drawing by Chris Pirillo)
\ . \ . \ . \ . \ .\ \.
\ . \. . \ . . \ . .\ . \. . \ . .
\\ . \\ . \\ . \\ .\\ \\ \\
\\ . \\ . \\ .\\ \\ \\ \\.
\\. \\ . \\ . \\ . \\ . \\ . \\
* . * . * . * . * . * . *
. . . . . .
. . . . .
. . . . . . . . . . .
. . . . . .
. . . . . . . . . . . . .
___/~\_/\____/~\_/\____/~\_/\____/~\_/\____/~\_/\____/~\_/\____/~\_/\_
_/~~\_ _/~~\_ _/~~\_ _/~~\_ _/~~\_ _/~~\_ _/~~\_ _/~~\_
. . . .
. . . .
+ + + + +
. . . .
* * * *
. . . .
. . . .
+ + + +
* * * *
. . . .
. . . .
. . . .
+ + + + +
. . . .
. . . .
* * * *
. . . . .
. . . .
+ + + + +
. . . .
* * * *
. . . .
* * * *
. . . .
. . . .
+ + + +
. ' . '
. ' * . ' * .
. . .
. ' . '
_' ____________________ ' ____________________ ' _
|____|~~ _ |____|~~ _ |____|
_ _
' = ' =
/ /
. -- ,.. / . -- ,.. /
,` '; ,` ';
.,.__ _,' /'; . .,.__ _,' /'; .
.:',' ~~~~ '. '~ .:',' ~~~~ '. '~
:' ( ) . ; ):;. :' ( ) . ; )::;.
'. '. .=----=..-~ .;' '. '. .=----=..-~ .;'
' ;' :: ':. '" ' ;' :: ':. '"
~~~~~~ (: ': ~ ;) ~~~~~~~ (: ': ~ ;) ~~~~~~~~~
'~ \\ '" ./ '~ \\ '" ./ '~
~ '" '" ~ '" '" ~
Subject: [8] Where is most of the discussion about SIRDS?
Most of the discussion about SIRDS has taken place in
alt.3d . A lot
of people would like to see the death of SIRDS, both due to the
overwelming number of people asking FAQ's, and simply because there is
much *much* better 3D out there than this!
Usually people post requests for information to newsgroups such as
comp.graphics...unfortunately these people sometimes get flamed, get
told it is *impossible* to draw them...if this has happened to you
read alt.3d , viva la difference.
Subject: [9] Internet locations for material
- Newsgroups
- alt.3d newsgroup
- (most SIRDS discussion is in this group)
- Ftp site
- ftp://katz.anu.edu.au/pub/stereograms (IP 150.203.7.91)
- Web pages (taken from Gareth and Peters page)
-
Picture Gallery, organised by Gareth and Peter, home of xpgs and SIRDSANI).
- Pascal
Massimino: "Chez Skal"
contains lots of pictures and some animations.
- Vern Hart:
"Vern's SIRDS Gallery"
has a comprehensive collection of SIRDSs & SISes.
- Jonathan Bowen:
"3-D and SIRDS images"
may be of interest as well.
- Jim Miller:
"The SGI Gallery (Jim's Gallery)"
has several `rastergrams'.
- Esa Kuru:
"True Color SIRDS" contain some interesting ideas and
attempts on how to put colour into SIRDS.
- Andreas Kahler:
"KALI's World of Stereograms (SIRDS & SIS)" holds some
good stereograms. Now has an English version of the front page.
- Gertjan van Oosten:
"SIRDS" contains an archive of autostereograms posted to
alt.3d.
- Keith Goldfarb:
"Keith's AutoStereoGram Page" has five autostereograms
on it.
- John Turner:
"John's Home Page" has some animated SIRDS.
- SoftSource:
"3d Stereographic Images" has SIRDS and SIS generated
from AutoCAD DXF files using their DXE library. Yet another NEW link.
- Peter Jennings:
"Stereograms" has some good stereograms. (The link is a bit
flaky from this end. Is netcom.com a bit overloaded?)
- Dale Harris:
"The Internet Railroad's Pix Archive" contains many of the
SIRDS posted to USENET.
- Cyrus Shaoul:
"Weird Three Dimensional Page!" has SIRDS done with xpgs!
- Heidrun
Kirchweger:
"3d collection" holds yet another archive of SIRDS &
SIS (from katz?).
- Marko Grobelnik:
"Stereogram Page" has a small archive of SIRDS (endlessly
duplicating ones which you can find in many of the links above). It's based
in Slovenia.
- Chris
Thornton:
"STEREO FLICKS" has a bunch of blocky SIRDS and a good
explanation of how they work.
- Andrew Giger:
"Andy's Stereograms" has some pretty SIRDS and SIRTS.
- Larry
Singleton:
"RDS & AutoS" is another entry in the vast list of
links that contains SIRDS & autostereograms from the net.
- Kurt Fleischer:
has made a SIRDS movie for Siggraph 94, a couple of frames from it are
available. There is also a `proper' colour SIRDS.
-
Chiangkai Er:
"Home Page" has SIS generated by a Pascal program he wrote.
- Mattan
Kamon:
"Random Dot Stereograms" has a couple of postscript SIRDS.
- Rob Malick:
"Stereogram directory (alphabetically)"has an(other)
archive of stereograms as part of his
Multimedia Lab.
- Blue Mountain Arts:
"5-D Stereograms Home Page" is a commercial page selling
5-D(tm) stereograms by Stephen Schutz. Don't know why they claim 5D
though because they seem to be just SISes.
- InterConnect West:
"Global Innovations" has a catalogue of commercial
colour stereogram posters.
Subject: [10] Stereogram History
-- Robert Raymond, Mirages -- Moab, Utah
Last updated: 28-June-1994 with comments from Jukka Hakkinen (jhakkine@cc.helsinki.fi)
- 1960
- Julesz, B. Binocular depth perception of computer generated
patterns. Bell Systems Technical Journal 39, 1125-1162. (First
article considering RDSs)
- 1962
- Julesz, B. and Miller, J. E. (1962) Automatic stereoscopic
presentation of functions of two variables. Bell System Technical
Journal. 41:663-676; March. Thimbleby (1990) refers to this article:
"Julesz and Miller were the first to show clearly that a sense of
depth could arise purely from stereopsis, without relying on other
cues such as perspective or contours. they used random patterns of
dots which, although meaningless to single eye viewing, nevertheless
created a depth impression when viewed in a stereoscope."
The following additional information about Julesz seems to be from The
Magic Eye, 1993, N.E. Thing Enterprises, Andrews and McMeel. I found
it quoted in a newspaper article:
During the 1960s, a researcher named Bela Julesz was the first to use
computer-generated 3-D images made up of randomly placed dots to study
depth perception in human beings. Because the dot pictures did not
contain any other information, like color or shapes, he could be sure
that when his subject saw the picture it was 3-D only.
In the years that followed, other people continued using random dot
pictures in their work; many of them were graduate students who
studied with Julesz. With time they found new and better ways to
create these interesting illusions.
- 1963
- Julesz, B Stereopsis and binocular rivalry of contours.
Journal of Optical Society of America 53, 994-999. (First article
which was accepted in a major US journal)
- 1964
- Julesz, B. Binocular depth perception without familiarity
cues. Science 145, 356-363. (First paper which was accepted in a
major international journal)
- 1965
- Bela Julez, "Textured and Visual Perception," Scientific American,
Feb. 1965. An article on stereo dot pictures. [George J Valevicius]
- 1966
- N. A. Valyus. Stereoscopy. Focal Press, London and New York. 426
pp. (I have not seen this book, but Boyer,1990 refers to it to say
that Stereographic paintings are almost beyond possibility.)
- 1968
- Bela Julez. "Experiment in Perception," Psychology Today, July 1968.
Cover story with a full page graphic and a few smaller ones.
- 1971
- Bela Julesz. Foundations of Cyclopean Perception. Chicago: Univ. of
Chicago Press. I have not seen this book, but Kinsman,1992 mentions
it: "Julesz (1971) describes photographic techniques producing random
dot stereograms in use in the early 1950s.... Since Julesz, in 1960,
was the first to employ a computer to generate random dot stereograms,
many would consider him the person most responsible for their
popularity today.... Anaglyphs of random dot stereograms... are
presented in the back of Julesz's book, and a pair of the
(half-red/half-green) glasses required to view them is tucked inside
the back cover."
- 1966
- Julesz, B. Binocular disappearance of monocular symmetry.
Science 153, 657-658. (Disparity cues can be more powerful than
monocular from cues)
- 1971
- Dr. Bela Julesz in "Reading from Scientific American - Image, Object
and Illusion" by W.H. Freeman Publisher ISBN 0-7167-0505-2 (1971).
[Bob Easterly]
- 1976
- Marr, D. and Poggio, T. (1976), Cooperative computation of stereo
disparity, Science, 194:283-287; October 15. Thimbleby (1990)
refers to this article: "[They] discuss computational models of the
visual processes that are involved in interpreting random dot
stereograms."
- 1977
- Bela Julesz. Foundations of Cyclopean Perception. University of
Chicago Press, Chicago. xiv, 406 pp. I assume this is the same
book as the 1971 book referenced by (Kinsman,1992). I think Boyer
gave the wrong publication date. Of the book, Boyer writes:
"The random-dot stereogram is a very inspiring demonstration of the
sophistication and complexity of the information-processing which
occurs in everyday human vision.... The first extensive studies of
random-dot stereograms were accomplished by Bela Julesz and his
colleagues on large and expensive computers, using professional
programmers, at the Bell telephone Laboratories." (Boyer,1990)
- 1977
- Tyler & Chang, Vision Research, #17. Referenced by Tyler, 1983.
- 1979
- Marr, D. and Poggio, T. (1979), A computational theory of human
stereo vision, Proceedings Royal Society of London, B204, 304:328.
Thimbleby (1990) refers to this article: "[They] discuss
computational models of the visual processes that are involved in
interpreting random dot stereograms."
- 1983
- Schor & Cuiffreda, editors. Vergence Eye Movements: Basic & Clinical
Aspects. One chapter, by Christopher Tyler including genuine SIRDS.
Interestingly, he doesn't say he invented them. He just calls them
"a new type of autostereogram designed for free fusion without the
need for a stereoscope or anaglyph glasses". Then he says the basis
is the repetition of a random pattern and refers to Tyler & Chang,
1977, Vision Res, #17. [Dan Richardson]
- 1985
- Paul S. Boyer. Stereographic technique for illustrating geologic
specimens. New Jersey academy of Science, Bulletin, volume 39, no.
2, pp. 83-91. I have not seen this article, but Boyer,1990 refers
to it when speaking of the DIN 4531 stereogram format.
- 1986
- L. L. Kontsevich. "An Ambiguous Random-Dot Stereogram Which
Permits Continuous Changing of Interpretation," Vision Research, Vol.
26, No. 3, pp. 517-519. I have not seen this article, but
Kinsman,1992 mentions it: "Kontsevich (1986) describes a technique for
making a series of tiles." Kinsman presents a "similar stereogram"
that is a SIRDS. If so, this would be the first SIRDS I am aware of.
- 1987
- Paul S. Boyer. Constructing true stereograms on the Macintosh. The
Journal of Computers in Mathematics and Science Teaching, volume 6,
no. 2, pp. 15-22. (I have not seen this article, but Boyer,1990
refers to it as a detailed article describing computer stereography.)
- 1988
- Falk, Brill and Stork produce the "Seeing The Light" image that
Dyckman referenced in his Stereo World article. [Dan Richardson]
- 1988
- J. Ninio and I. Herlin. "Speed and Accuracy of 3D Interpretation of
Linear Stereograms, Vision Research, Vol. 28, No. 11, pp.
1223-1233. I have not seen this article, but Kinsman,1992 mentions
it: "Ninio and Herlin (1988), and Slinker and Burton (1992),
experimented with stereograms containing complex patterns [triangles,
lines, blotches, and even images] in their initial noise fields."
- 1989
- Rocca and Stork, Behavior Research Methods, Instruments and
Computers, 1989, might be vol 21 number 5. Demonstrats a little Mac
program they wrote to generate SIRDS from MacPaint files.
[Dan Richardson]
- 1990
- Paul S. Boyer, Professor of Geology, Fairleigh Dickinson University,
"Random-Dot Stereograms -- Creating a Psychological Phenomenon,"
STEREO WORLD, March/April 1990. Creating SIRDS on the Mac.
- 1990
- Tyler, C. W. and Clarke, M. B. (1990) The autostereogram. SPIE
Stereoscopic Displays and Applications 1258: 182-196. Thimbleby
(1990) refers to this article: "Recently, however, Tyler and Clarke
realized that a pair of random dot stereograms can be combined
together, the result being called a single image random dot
stereogram (SIRDS) or, more generally, an autostereogram.... [They]
described a simple but asymmetric altorithm, which meant, for
example, that some people can only see the intended effect when the
picture is held upside-down."
- 1990
- Dan Dyckman, "Single Image Random Dot Stereograms," STEREO WORLD,
May/June 1990. "I was recently surprised when a friend of mine ...
showed me a random-dot-stereograph that consisted fo a single image,
rather than the usual stereo pair. To view the image, one fused two
marks within the image, and would see the words SEEING THE LIGHT."
"Interested readers might consider creating poster-sized images using
this technique, or experimenting with supplementary gray-level or
color values for each pixel. And, if any reader knows who invented
this technique for single image random dot sstereograms, or who
created the SEEING THE LIGHT image, please drop a note to this
magazine."
- 1991
- Prior to June 1991 a company named Pentica Systems, Inc (One Kendall
Square, Building 200, Cambridge, MA 02139, Tel. 617-577-1101, Tom
Baccei - President) published an advertisment, "Pentica Loves
Puzzles," with a SIRDS image in it. The magazine may have been EDN--I
don't remember.
- 1991
- About June 3, 1991, Pentica mails an information packet to those
responding to the add. In the information Pentica sent to those
responding to the ad, they say, "We discovered ... the technique for
generating it in STEREO WORLD." Four SIRDSs accompany the information,
marked "images (c) 1990 by Dan Dyckman."
- 1991
- June 13, 1991, N.E. Thing Enterprises, (One Kendall Square, Building
200, Cambridge, MA 02139) also mails a flyer to those responding to
the Pentica ad. The N.E.Thing address and the Pentica address are the
same, as well as the postal meter number (FMETER 8010560) for the two
mailings. The flyer states, "from the people who created the Pentica
Loves Puzzles Ad.... Because of the unbelievably enthusiastic
response to our random dot stereogram featured in the 'Pentica Loves
Puzzles' ad, we are rushing you this advance notice of our latest 3D
mindbenders." They offered 3 posters, World's Hardest Maze, The Third
Eye, Training Wheels, and a 1992 Calendar.
- 1992
- Andrew A. Kinsman, Random Dot Stereograms, Kinsman Physics, 1992.
First printing October 1992. "This history of the stereogram is a bit
elusive. It appears to be intertwined with anaglyphs, lenticular
photographs, and stereoscopic photographic techniques. Charles
Wheatstone described stereoscopy in 1832. In 1851 the the London
Society of Arts held the Crystal Palace Exhibition, which six million
people attended and potentially witnessed Sir David Brewster
demonstrate the stereoscope. Stereoscopes became popular as a result.
Kahn (1967), in The Codebreakers, references an article by Herbert C.
McKay, written in the late 1940s, on how to manufacture simple
stereograms with a typewriter for encryption purposes.... Julesz
(1971) describes photographic techniques producing random dot
stereograms in use in the early 1950s. History seems to have recorded
no particular inventor of stereograms. It is quite probable that soon
after parlor-style stereoscopes became popular someone took a
photograph of a camouflaged hunter with a stereo camera. The subject
in the resulting picutre might be difficult to identify. Viewed
stereoscopically with the rest of their collection, the subject would
become obvious."
- 1992
- "This unique synthesis of computer technology and fine art began simply
as an idea between two creative individuals in 1992. Paul's art
background and Mike's computer genious proved to be the perfect
combination of talents. Several hundred man hours later, in a remote
region of California, came the first public exposure to Holusion(TM)
3D Prints. And so NVision Grafix was born." (NVision Grafix flyer
introducing Calypso Reef, 1993.) "Micro Synectic was Mike Bielinski is
NVision...NE Thing and Micro Synectics are listed in the StareEO demo,
because Mike Bielinski wrote it for NE Thing." (CompuServe messages
from Dan Richardson) "The images are the creation of NVision Grafix, a
Texas-based firm owned by two former fraternity brothers, Paul Herber
and Mike Bielinski. They developed the Holusion technology while
making a poster of the B-2 bomber for the company where Herber worked
as an engineer. The posters were a huge hit, and soon, Herber and
Bielinski had abandoned their jobs to start up NVision: Herber is the
artist, and Bielinski is the computer whiz.... As NVision has grown,
though so has it's competition. Computer expert Tom Baccei has created
his won "high-tech, three-dimensional art form" under the name "Magic
Eye" and is marketing the images on books, posters, calendars, puzzles
and cards." (Nicole Brodeur, Orange County Register. As reprinted in
The Daily Herald, March 22, 1994)
- 1993
- N.E. Thing begins patent process on several RDS algorithms. "Salitsky
dot" algorithm and the algorithm to produce an RDS that looses it's
colors when viewed in 3D are apparently two algorithms. I have not
seen the patent applications, but the law requires that they discuss
"prior art." If someone could get copies of these applications, it
would not only describe the algorithms in detail, it would present a
history of SIRDS, to the degree that N.E. Thing was aware.
- 1993
- Harold W. Thimbleby, Stuart Inglis, and Ian H. Witten, "Displaying 3d
Images: Algorithms for Single Image Random Dot Stereograms,"
University of Waikato, Hamilton, New Zealand, published on the
Internet. I believe Stuart mentioned it was being published in an
IEEE journal in 1994. I've forgotten which one and when. [IEEE Computer, soon - S.]
-- A few historical comments by jhakkine@cc.helsinki.fi
There was a good article about the early history of RDSs in Vision
Research (Julesz (1986), Vision Research vol. 26 no. 9, 1601-1612).
Julesz who himself was a radar engineer tells that the first RDS
was accidentally taken by a photographic Spitfire flying over Cologne
in 1940! (The picture has been published by Smith (Perception 1977,
vol.6, 233-234)). The picture consists of some city blocks, a bridge
and the river Rhine which is covered by ice. Because the ice is floating
downriver and the pictures are taken at slightly different times,
the ice patterns are slightly different in two stereopairs. This
results a depth parallax between the pictures and when they are
stereoscopically fused there seems to be a deep valley in the middle
of the river. This caused great confusion in the wartime RAF but
no-one could make up an explanation to the phenomenon because at the
time there was no knowledge about stereoscopic processes working
without monocular pattern recognition.
Julesz also mentions that there had been some prior attempts to
make RDSs (Aschenbrenner, C.M. (1954) Problems in getting
information into and out of air photographs. Photogramm.Engng. 20,
398-401) but without a noticeable succes because the pictures
had been hand cut. Because the methods had been so crude there
was a good possibility that these pre-RDSs contained monocular
depth cues. Julesz created his stereograms with a computer
so they were very precise and the possibility of monocular cues was
nonexistent. Naturally the leading researchers at the time (Ogle &
Wakefield (1967) Vision Research vol.7, 89-98) did not believe that
it was possible and the notion of depth perception without
monocular cues remained controversial for a long time.
Ogle & Wakefield (1967):
"One obtains the impression from some of Julesz's interesting
experiments that certain targets yield a stereoscopic depth,
but contours cannot be perceived monocularly. However, the
stereoscopic depth experienced in the central portion is that
of a defined square proximal or distal to the background,
determined precisely by the "lines" he "cut" in the background
patterns of random details in each of the stereogram pairs.
It is difficult to believe that a "cut" and displacement of
random patterns - unless the details of patterns are exceedingly
small - result in a randomness on the two sides of the cut.
Some of the dots could have been split. It may be true that
monocularly the contours may be difficult to perceive, but still
we wonder if they are not perceivable."