[Coco] [Color Computer] DjVu misconceptions

[James Diffendaffer]

Ok, I've seen several people call DjVu a "new" format, an obscure
format or whatever.

To clear things up and provide a little background on the format.

DjVu is based on fractal image compression.  Info was published on
fractal image compression in Byte magazine in 1988.  Do a google
search on fractal compression and you will spend a long time looking
through the links.  With DjVu being the most prominant format within
the fractal research commmunity it is far from obscure.  It obviously
isn't on most people's computers like Acrobat reader.

DjVu was introduced around 1991.  The group I was working with at the
time was looking at it and a wavelet based compression for use in a
project.  That's around the same time PDF was intruduce... so the
formats are about the same age.  Those two and another format failed
to catch on till Adobe distributed the free viewer and dropped the
absurd license fees.  Once the word free was attached to the PDF
format it took off.  (though it is far from totally free)

The first patent related to the compression used by DjVu was granted
10 July 1990 to its creator's company Iterated Systems, Inc.  
Additional patents were issued in 1991, 1995 and 1995.  2 are specific
to hardware and aren't really an issue.

Patents now last 20 years but patents applied for prior to June 8th
1995 last the previous 17 years.  The last patent I found was issued
at the beginning of July 1995... so it obviously falls under the prior
patent rules and the US software patents may not apply outside the US
at all.  The patents will start to expire within the next couple
years.  There may be additional patents but they will be related to
specific implementations and may not be held by the original patent
holder. 

What is fairly new is that Lizzard Tech recently changed the DjVu
license terms in hope that it could make some money from it's tools
prior to the expiration of the patents.  More recently was the
creation of the open source projects on sourceforge.  

Since the change in license terms the format's use has started to take
off just like PDF did when it's license terms changed.





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