```....................................
..#####..######.....#####...######..
.#.....#.#.....#...#.....#..#.....#.
.......#.#.....#.........#..#.....#.
..#####..#.....#....#####...#.....#.
.......#.#.....#.........#..#.....#.
.#.....#.#.....#...#.....#..#.....#.
..#####..######.....#####...######..
....................................
```

ASCII Stereograms

Jonathan Bowen

Originally written 11th August 1992 Reformatted in HTML and updated, 25th May 1999

Here are some ASCII stereograms for your enjoyment (e.g., see Figure 1). To obtain the 3-D effect, you need to diverge (unfocus) your eyes such that two adjacent letters in the same row come together. To help you focus, 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 you have done that, look down at the rest of the image and the 3-D effect should jump out at you! If you make the Os at the bottom look like three then the effect is reversed. It is also possible to get opposite 3-D effects by crossing your eyes rather than diverging them, although some people find this harder to do (including me!).

Figure 1: Near and far distances.

```                             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
```

Figure 2 demonstrates the effect even more dramatically. Try moving your head back from the screen once you have focused on the image to increase the stereo effect even more. You can also move it horizontally and vertically a little and observe the effect.

Figure 3 shows a single image random text stereogram (SIRTS) based on the same idea as a single image random dot stereogram (SIRDS). You should see the word ``Hi'' in relief when the image clicks into place.

Some people include stereograms in their ``signatures'' at the end of electronic mail messages and news articles; see for example Figure 4.

Figure 2: A floor, wall and ceiling.

```                           O          O
.  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
.   .   .   .   .   .   .   .   .   .   .   .   .   .   .   .   .
.    .    .    .    .    .    .    .    .    .    .    .    .
.     .     .     .     .     .     .     .     .     .     .
.      .      .      .      .      .      .      .      .
.       .       .       .       .       .       .       .       .
.        .        .        .        .        .        .
.         .         .         .         .         .         .
.          .          .          .          .          .          .
|          |          |          |          |          |          |
|          |          |          |          |          |          |
|          |          |          |          |          |          |
|          |          |          |          |          |          |
|          |          |          |          |          |          |
|          |          |          |          |          |          |
.         .         .         .         .         .         .
.        .        .        .        .        .        .
.       .       .       .       .       .       .       .       .
.      .      .      .      .      .      .      .      .
.     .     .     .     .     .     .     .     .     .     .
.    .    .    .    .    .    .    .    .    .    .    .    .
.   .   .   .   .   .   .   .   .   .   .   .   .   .   .   .   .
.  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .  .
```

Figure 3: A single image random text stereogram.

```                      O              O
OIWEQPOISDFBKJFOIWEQPOISDFBKJFOIWEQPOISDFBKJFOIWEQPOISDFBKJF
EDGHOUIEROUIYWEVDGHOXUIEROIYWEVDGHEOXUIEOIYWEVDGHEOXUIEOIYWE
KJBSVDBOIWERTBAKJBSVEDBOIWRTBAKJBSOVEDBOWRTBAKJBSOVEDBOWRTBA
SFDHNWECTBYUVRGSFDHNYWECTBUVRGSFDHCNYWECBUVRGSFDHCNYWECBUVRG
HNOWFHLSFDGWVRGHNOWFGHLSFDWVRGHNOWSFGHLSDWVRGHNLOWSFGLSDWVRG
YPOWVXTNWFECHRGYPOWVEXTNWFCHRGYPOWNVEXTNFCHRGYPWOWNVETNFCHRG
SVYUWXRGTWVETUISVYUWVXRGTWVETUISVYUWVXRGWVETUISVYUWVXRGWVETU
WVERBYOIAWEYUIVWVERBEYOIAWEYUIVWVERBEYOIWEYUIVWLVERBEOIWEYUI
EUIOETOUINWEBYOEUIOEWTOUINWEBYOEUIOEWTOUNWEBYOETUIOEWOUNWEBY
WFVEWVETN9PUW4TWFVEWPVETN9UW4TWFVETWPVET9UW4TWFBVETWPET9UW4T
NOUWQERFECHIBYWNOUWQXERFECIBYWNOUWFQXERFCIBYWNOFUWFQXRFCIBYW
VEHWETUQECRFVE[VEHWERTUQECFVE[VEHWQERTUQCFVE[VEOHWQERUQCFVE[
UIWTUIRTWUYWQCRUIWTUYIRTWUWQCRUIWTXUYIRTUWQCRUIBWTXUYRTUWQCR
IYPOWOXNPWTHIECIYPOWTOXNPWHIECIYPONWTOXNWHIECIYLPONWTXNWHIEC
R9UHWVETPUNRQYBR9UHWVETPUNRQYBR9UHWVETPUNRQYBR9UHWVETPUNRQYB
```

Figure 4: A stereogram signature.

``` IIIIIIIIIIIIIII   IIIIIIIIIIIIIII    Marty Hewes
H ( )  \|/    H   H   ( )   \|/ H    Tellabs Inc.
H(   ) -O-    H   H  (   )  -O- H    System and Applications Test
H     )/|\    H   H (     ) /|\ H    Lisle, Il
H======^======H   H======^======H    nitram@tellabs.com
H- |----@-----H   H----| ---@---H    uunet!tellab1.TELLABS.COM!nitram
H /|\ @\|/ @  H   H   /|\@ \|/@ H
H    \|/  \|/ H   H     \|/  \|/H    W (708) 955-3038
III^IIIIIII^III   III^IIIIIII^III    H (708) 665-6671
Wide eyed stereo  Wide  eyed  stereo
```

Acknowledgements

Figures 1, 3 and 4 are due to David B. Thomas, Charles Durst and Marty Hewes respectively. All these stereograms appeared on the alt.3d USENET newsgroup, which is recommended reading for stereogram addicts.