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Originally Posted by Gudy
Eh? Says who? There was a big noise a couple of years ago when some firm which had acquired the patent for the LZW(?) compression used in GIF image files started successfully enforcing said patent. If nothing else, it gave the hitherto lingering PNG format a nice boost.
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That was Unisys.
Lev and Zemple defined the original algorithm. Terry Welch described a simplified version that was easier to implement, becoming the W in LZW. At the time he wrote the paper describing the LZW algorithm, Terry worked for Sperry, now a unit of Unisys, and his contract gave his employer rights to his creations.
Unisys belatedly woke up, realized they had intellectual property rights to LZW compression, and started asking for money from sites with GIF images that used LZW compression.
As mentioned, it resulted in the PNG format, and it's a moot point now -- as far as I know, Unisys's rights have expired.
I wonder how much money they actually got from trying to enforce rights on LZW? I suspect not as much as they spent in legal fees doing it.
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Legally speaking, the Mobipocket compression scheme is probably not part of their DRM, so you likely don't have to fear the DMCA, but it may very well be covered by a patent. This patent in all likelihood would also cover a decompression routine for the compressed data.
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If it
is covered by patent, that will be discoverable. I doubt it, though. I suspect this is "trade secret" -- they just don't tell anyone what they did and how they did it.
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Dennis