[Reply]
At 20:30 on 29/09/1999 Tony wrote
> There are so many responses to this topic! and it seems to have drifted a
> long way of topic. Could some one please somerise for me what I
> legally may
> and may not do with GIFS.
I went into this some time ago. The history of GIF was that it was originally adopted
by Compuserve as their
preferred method of exchanging graphical data over their network of users, hence the
name Graphical Interchange
Format. (GIF). Well all went well for many years until it dawned on someone at Unisys
that GIF used one of their
algorithms developed, or rather enhanced by one of their employees (Welch) of the
original algorithm developed by
Lempel and Zif. Actually they had to be told!!
Anyway, Unisys lawyers realised that by allowing GIF to run free in the marketplace
compromised their charging for
royalities for the hardware implementations of LZW as found in most hard drive
controllers etc - a very lucrative
source of income for them.
Anyway, to cut a long story short, until 2003, when the patent runs out, any software
developer who creates
a GIF loader or saver, must pay royalties to Unisys.
For more information go look at
http://cloanto.com/users/mcb/19950127giflzw.html.
Also Dave Baldwin (of THML fame - http://www.pbear.com ) has more data and links on
his web page to the Unisys
contact for patent payments .....
Kindest Regards
Gary
PS: To confuse the issue, IBM patented the same algorithm before Unisys. The IBM
patent application was filed three
weeks before that of Unisys, but the US patent office apparently failed to recognize
that they covered the same
algorithm. (The IBM patent is more general, but its claim 7 is said to be exactly
LZW.) British Telecom and Japanese
companies also hold patents for LZW equivalent algorithms.
========================================================
Gary Benner - Software Developer [EMAIL PROTECTED]
Corporate Software New Zealand Limited Auckland - New Zealand
tel: +64-9 846-6067 (24hr) fax: +64-9 846-6152 mob: (021)-966-992
Software System Design - Consulting - Mentoring - Data Modelling
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http://www.corporate.co.nz
Ref#: 41006
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