ASCII stereogram
Encyclopedia
ASCII stereograms are a form of ASCII art
based on stereogram
s to produce the optical illusion
of a three-dimension
al image
by crossing the eyes appropriately using a single image or a pair of images next to each other.
To obtain the 3D effect (in Figure 1 for instance), it is necessary for the viewer to diverge their eyes such that two adjacent letters in the same row come together. To help in focusing, try to make the two capital Os at the top look like three. Ensure that the image of the central dot is stable and in focus. Once this has been done, look down at the rest of the image and the 3D effect should become apparent. If the Os at the bottom of Figure 1 look like three, then the effect is reversed. It is also possible to obtain opposite 3D effects by crossing the eyes rather than diverging them.
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Figure 1: Near and far distances.
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Figure 2 demonstrates the effect even more dramatically. Once the 3D image effect has been achieved, moving the viewer's head away from the screen increases the stereo effect even more. Moving horizontally and vertically a little also produces interesting effects.
Figure 3 shows a Single Image Random Text Stereogram (SIRTS) based on the same idea as a Single Image Random Dot Stereogram (SIRDS). The word "Hi" in relief can be seen when the image clicks into place.
Some people have included stereograms in their "signature" at the end of electronic mail messages and news articles. Figure 4 is such an example.
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Figure 2: A floor, wall and ceiling.
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Figure 3: A single image random text stereogram.
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Figure 4: A stereogram signature.
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Moving animated versions of ASCII stereograms are possible too.
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Figure 5: Emphasized single words.
, Charles Durst and Marty Hewes respectively. These four stereograms appeared on the publicly accessible alt.3d USENET
newsgroup
. Figure 5 was invented on the spot by a Wikipedian.
Originally adapted from an article on ASCII Stereograms by the author of that article (and with his permission).
ASCII art
ASCII art is a graphic design technique that uses computers for presentation and consists of pictures pieced together from the 95 printable characters defined by the ASCII Standard from 1963 and ASCII compliant character sets with proprietary extended characters...
based on stereogram
Stereogram
A stereogram is pair of two-dimensional panels depicting the view of a scene or an object from the vantage points of the right and left eyes. Observing the panels superimposed in a stereoscope results in the experience of three-dimensionality by virtue of the fact that object depth is encoded as...
s to produce the optical illusion
Optical illusion
An optical illusion is characterized by visually perceived images that differ from objective reality. The information gathered by the eye is processed in the brain to give a perception that does not tally with a physical measurement of the stimulus source...
of a three-dimension
Dimension
In physics and mathematics, the dimension of a space or object is informally defined as the minimum number of coordinates needed to specify any point within it. Thus a line has a dimension of one because only one coordinate is needed to specify a point on it...
al image
Image
An image is an artifact, for example a two-dimensional picture, that has a similar appearance to some subject—usually a physical object or a person.-Characteristics:...
by crossing the eyes appropriately using a single image or a pair of images next to each other.
To obtain the 3D effect (in Figure 1 for instance), it is necessary for the viewer to diverge their eyes such that two adjacent letters in the same row come together. To help in focusing, try to make the two capital Os at the top look like three. Ensure that the image of the central dot is stable and in focus. Once this has been done, look down at the rest of the image and the 3D effect should become apparent. If the Os at the bottom of Figure 1 look like three, then the effect is reversed. It is also possible to obtain opposite 3D effects by crossing the eyes rather than diverging them.
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O O
n 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 f
e 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 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 r r
O O
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Figure 2 demonstrates the effect even more dramatically. Once the 3D image effect has been achieved, moving the viewer's head away from the screen increases the stereo effect even more. Moving horizontally and vertically a little also produces interesting effects.
Figure 3 shows a Single Image Random Text Stereogram (SIRTS) based on the same idea as a Single Image Random Dot Stereogram (SIRDS). The word "Hi" in relief can be seen when the image clicks into place.
Some people have included stereograms in their "signature" at the end of electronic mail messages and news articles. Figure 4 is such an example.
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O O
. . . . . . . . . . . . . . . . . . . . . . .
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O O
OIWEQPOISDFBKJFOIWEQPOISDFBKJFOIWEQPOISDFBKJFOIWEQPOISDFBKJF
EDGHOUIEROUIYWEVDGHOXUIEROIYWEVDGHEOXUIEOIYWEVDGHEOXUIEOIYWE
KJBSVDBOIWERTBAKJBSVEDBOIWRTBAKJBSOVEDBOWRTBAKJBSOVEDBOWRTBA
SFDHNWECTBYUVRGSFDHNYWECTBUVRGSFDHCNYWECBUVRGSFDHCNYWECBUVRG
HNOWFHLSFDGWVRGHNOWFGHLSFDWVRGHNOWSFGHLSDWVRGHNLOWSFGLSDWVRG
YPOWVXTNWFECHRGYPOWVEXTNWFCHRGYPOWNVEXTNFCHRGYPWOWNVETNFCHRG
SVYUWXRGTWVETUISVYUWVXRGTWVETUISVYUWVXRGWVETUISVYUWVXRGWVETU
WVERBYOIAWEYUIVWVERBEYOIAWEYUIVWVERBEYOIWEYUIVWLVERBEOIWEYUI
EUIOETOUINWEBYOEUIOEWTOUINWEBYOEUIOEWTOUNWEBYOETUIOEWOUNWEBY
WFVEWVETN9PUW4TWFVEWPVETN9UW4TWFVETWPVET9UW4TWFBVETWPET9UW4T
NOUWQERFECHIBYWNOUWQXERFECIBYWNOUWFQXERFCIBYWNOFUWFQXRFCIBYW
VEHWETUQECRFVE[VEHWERTUQECFVE[VEHWQERTUQCFVE[VEOHWQERUQCFVE[
UIWTUIRTWUYWQCRUIWTUYIRTWUWQCRUIWTXUYIRTUWQCRUIBWTXUYRTUWQCR
IYPOWOXNPWTHIECIYPOWTOXNPWHIECIYPONWTOXNWHIECIYLPONWTXNWHIEC
R9UHWVETPUNRQYBR9UHWVETPUNRQYBR9UHWVETPUNRQYBR9UHWVETPUNRQYB
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IIIIIIIIIIIIIII IIIIIIIIIIIIIII
H \|/ H H \|/ H
H( ) -O- H H ( ) -O- H
H )/|\ H H ( ) /|\ H
H^
H H^
H
H- |----@-----H H----| ---@---H
H /|\ @\|/ @ H H /|\@ \|/@ H
H \|/ \|/ H H \|/ \|/H
III^IIIIIII^III III^IIIIIII^III
Wide eyed stereo Wide eyed stereo
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Moving animated versions of ASCII stereograms are possible too.
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Text Emphasis
The stereo effect can be used to highlight individual words in a text, as a sort of "secret message". The effect can be disguised when the paragraph is block justified.----
According to the According to the
police inspector, police inspector,
Edward John Billings, Edward John Billings,
there are too many there are too many
individuals too close individuals too close
to the case to make to the case to make
an arrest. I asked an arrest. I asked
Mary Smith to comment Mary Smith to comment
on the case, but she on the case, but she
declined to comment, declined to comment,
because she is soon because she is soon
to be married to to be married to
Howard D. Fredericks, Howard D. Fredericks,
the victim's uncle. the victim's uncle.
Charles Wilson, the Charles Wilson, the
victim's brother, victim's brother,
stated that the chaos stated that the chaos
was responsible for was responsible for
at least five suicide at least five suicide
attempts last week attempts last week
alone. alone.
Acknowledgements
Figures 1, 2, 3 and 4 are due to David B. Thomas, Jonathan BowenJonathan Bowen
Jonathan P. Bowen FBCS FRSA is a British computer scientist. He is Chairman of Museophile Limited, an Emeritus Professor at London South Bank University where he has headed the Centre for Applied Formal Methods, and a Visiting Professor at the University of Westminster...
, Charles Durst and Marty Hewes respectively. These four stereograms appeared on the publicly accessible alt.3d USENET
Usenet
Usenet is a worldwide distributed Internet discussion system. It developed from the general purpose UUCP architecture of the same name.Duke University graduate students Tom Truscott and Jim Ellis conceived the idea in 1979 and it was established in 1980...
newsgroup
Newsgroup
A usenet newsgroup is a repository usually within the Usenet system, for messages posted from many users in different locations. The term may be confusing to some, because it is usually a discussion group. Newsgroups are technically distinct from, but functionally similar to, discussion forums on...
. Figure 5 was invented on the spot by a Wikipedian.
Originally adapted from an article on ASCII Stereograms by the author of that article (and with his permission).
External links
- 3D Stereogram Ascii Image Generator and Movie Generator
- ASCII Stereograms by Jonathan BowenJonathan BowenJonathan P. Bowen FBCS FRSA is a British computer scientist. He is Chairman of Museophile Limited, an Emeritus Professor at London South Bank University where he has headed the Centre for Applied Formal Methods, and a Visiting Professor at the University of Westminster...
- ASCII art stereogram generator from AA-Project
- IOCCC 2001 winner "herrmann2", an ASCII stereogram generator (for which the source code is itself an ASCII stereogram)
- Online ASCII Stereogram Generator
- Basic ASCII Stereogram Maker