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Stereograms
version 1.0
A Little Known Fact About This Program
Stereograms was the
program used by the Dave Mathews
band to create the cover of their first album, Remember Two Things
What are stereograms?
A stereogram is a two
dimensional picture (either on your computer screen or printed on
a piece of paper) that can appear three dimensional (like holograms)
when viewed properly. To view a stereogram properly, each eye must
focus on a different half of the stereogram, leaving the brain to
fuse the two images together into one three dimensional image.
Helpful
Ways to See the 3D Image:
*Make sure the
stereogram is oriented parallel to your eyes. If you tilt your head
sideways at all, the 3 dimensional image (stereogram) will disappear.
* Try to let the individual dots (pixels) go blurry. Pretend you
are focusing on an object 6-12 inches past the stereogram (this
should make the dots blurry).
* Place the stereogram in a well lit room.
* Relax your eyes and try to visually "drift" into the stereogram
image.
* Place the stereogram behind a reflective surface, like a glass
picture frame, and stare at your reflection. Your computer screen
is such a surface. Alternatively focus on the stereogram and then
at your reflection, since the 3D image lies somewhere between these
two focus points.
* Try viewing the stereogram from extremely different distances
(place it at your nose or across the room).
* Place the stereogram at the end of your nose, look straight ahead,
and slowly move the stereogram away from you.
How does my program
create stereograms?
The program needs
two things from you to create a stereogram: a depth bitmap
with the numerical depths (or elevations) assigned and a background
tile (which can either be a tile, or just randomly colored dots).
The depth bitmap with
its numerical depths (or elevations) tells the program the depth
(ie. how far off the screen or page each point should "float").
A simple depth bitmap might just be some concentric squares: Each
color would then be assigned a unique elevation value (a number
from 0 to 255) to represent its "elevation" (or distance that point
should float above the screen). If a color is assigned the number
zero, it won't "float" in front of the screen at all while a value
of 20 indicates that a color should float 20 units above the screen.
The background tile picture
is the picture which the program manipulates to create your final
stereogram. The program scans through each pixel of the background
tile picture (a row at a time) and makes copies of some of the pixels
and shifts them to the right. The numerical depth value (or elevation)
for the corresponding pixel in the depth bitmap determines how far
to the right a pixel is shifted in the background tile. The picture
that results from all the shifting of pixels is called a stereogram.
Here
is an original picture that was converted into a stereogram

This is the resulting stereogram image created
by the program.
Can you see the 3D skindiver and the fish?

Note: This
program was originally developed by Jeff Smith and Rick Kwiatkowski.
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