Welcome to Rich Franzen's
(Portable Network Graphics)
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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
which I wrote several years ago.
Bookoo Colors and Greys
For an interesting complement to the above Image of 65536 Greys
play with my interactive Page of 60,480 Colors
For you square-snake lovers, click on over to the original
home of pseudoGrey
See how to squeeze 1786 levels of grey from an image which only
(64x64 by 24 bits)
1786 levels of grey
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.
115 kbytes, 599x477 pixels, 8-bit image
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
. 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
The optical illusion of motion reminds me of the quest to build a
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
Museum of Unworkable Devices
is another great site (which unfortunately uses GIF images).
... <sigh> Maybe it's a doctor thing ...
134x124 by 64 greys
Full Color Break!
Check out the PNG'd
Use above link to get to all 24 thumbnails.
The images are large, 24 bits, and lossless.
Monitoring the Monitor
This monitor test image was built years ago
by Chris Eizember of DuPont on their NDT Scan IV
The two files below are the same
the one on the left was saved using PNG's Adam7 interlacing format.
4096x4096 by 12 bits/pixel (2 bytes/pixel)
Actual 16-bit Scan
Source image was a very old lab film. Scratches are real!
Graphics at Work
, 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
Accesses since 1998-08-15
Last updated 2013-06-15
Fishbowl Globe by Diana Todd