Just Say No to GIFs
If you run a web site please try to avoid using .gif format. Use .png for images that must be lossless and use .jpeg for imagery where lossy compression is OK. It's not just good technology
it's also a matter of ethics. Here's why:
The LZW (Lempel-Ziv-Welch) algorithm for compression in software has been
patented not once but several times: It has been patented by both IBM (U.S. patent
4,814,746) and Unisys (U.S. patent 4,558,302). British Telecom has also been
awarded a similar patent in the UK. IBM's patent was filed three weeks before
the Unisys application. Both patents were granted in 1983. In a typically
inept maneuver the U.S. patent office issued patents to both IBM and Unisys for the
same algorithm, apparently not realizing that the patents covered the same
"invention."
.gif was developed by CompuServe and published as an "open" format in the 1980's
without realizing that the LZW compression used to create compressed .gif files could be subject to patent claims by Unisys or the other LZW patent
holders. Based on the alleged "open" nature of .gif it became a widely used format. At some point, Unisys became aware that .gif files were created using LZW and decided to begin "enforcing" its LZW patent.
Unisys has sought to extract money payments from companies who create software
that writes .gif files, in particular in 1994 and 1995 launching a series of initiatives that
successfully alienated numerous software developers. At one point, Unisys
claimed to be able to require royalty payments from every web site that had a .gif image in it. In contrast, IBM has never sought to enforce its LZW patent
against .gif developers and users.
In 1995 CompuServe launched the GIF 24 initiative, to develop a replacement
for .gif not held hostage by software patents. Other developers launched the GEF
initiative, which soon converged with GIF 24 to create .png. .png is a true "open" format not subject to patent claims by anyone. It is more
efficient than .gif to boot and a much better choice for network graphics in the modern age.
Many developers and patent attorneys feel that it is only an accident caused
by the ineptness of the U.S. patent office that Unisys was awarded a patent on
LZW compression in the first place. Many developers feel so badly about
Unisys's campaign that they have pledged to maintain only ".gif free" web sites and to avoid purchasing Unisys products or services. See http://burnallgifs.org for an example of some developer feedback on Unisys and .gif.
At manifold.net we now use .png format instead of .gif for all graphics publication on web sites. We have done so mainly because .png provides better compression and thus better performing web sites for lower
bandwidth. Even so, it's also nice to know that with every .gif replaced with a .png we help strike one more blow against wrongheaded patent policies.
Remember: friends don't let friends drive drunk, and they don't let them use .gif either!
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