Square Snakes
The above image contains 4096 shades of grey.
You will see an image with lots of shades of grey by clicking above.
The raw pixels for both "snakes" were generated with
a
program which I wrote several years ago.
Round Snakes
I have not forgotten the round snake lovers, but
caution!
The following image uses an "anomalous motion illusion", which might make
sensitive observers dizzy or sick. Should you feel dizzy, you had better
scroll past this image quickly.
rotsnake_cropped.png,
115 kbytes, 599x477 pixels, 8-bit image
from
Rotating Snakes,
Copyright A.Kitaoka 2003
No, it's not really moving.
At least I don't think it's moving...
Clicking the image above brings you to the English version of
Akiyoshi's illusion
pages. Dr. Akiyoshi Kitaoka is an Associate Professor of psychology at
the College of Letters, Ritsumeikan University, Kyoto, Japan. Unfortunately
his site uses mostly GIF images along with a few JPEG images. Even so, they
are amazing!
The optical illusion of motion reminds me of the quest to build a
perpetual motion
"
overbalanced wheel".
In the case of the rotating snakes, though, your eye and mind make it work.
Dr. Donald Simanek is Professor of Physics at Lock Haven University of
Pennsylvania. His
Museum of Unworkable Devices
is another great site (which unfortunately uses GIF images).
... <sigh> Maybe it's a doctor thing ...
cage-t.png134x124 by 64 greys
Monitoring the Monitor
This monitor test image was built years ago
by Chris Eizember of DuPont on their
NDT Scan IV system.
The two files below are the same
SMPTE RP-133 image;
the one on the left was saved using PNG's Adam7 interlacing format.
4096x4096 by 12 bits/pixel (2 bytes/pixel)
Graphics at Work
401k1.png, Business Graphics Example
14 kbytes (616x472 by 5 bits)
equivalent GIF is 26 kbytes — 75% quality JPEG is 38 kbytes
Check out this clean, business-oriented
slide-show.