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When this HooHa started I was under the impression that the algorithm
was patented _after_ CS produced the GIF format but before Unisys was
involved. I was wrong?
--
Alf
http://www.peake42.freeserve.co.uk/
http://ourworld.compuserve.com/homepages/Alf_Peake/
Mark Gordon <mtg### [at] mailbag com> wrote in message
news:393EE7E5.84E8A8E6@mailbag.com...
> David wrote:
>
> > Did Unisys even make the GIF format?
>
> CompuServe made the GIF format, using an algorithm that they did not
> realize had been patented by a company that had subsequently been
> purchased by Unisys. Had CompuServe known the algorithm was
encumbered
> by a patent, they probably would have chosen a different algorithm.
>
> -Mark Gordon
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Alf Peake wrote:
>
> When this HooHa started I was under the impression that the algorithm
> was patented _after_ CS produced the GIF format but before Unisys was
> involved. I was wrong?
Digging out books...
1984 - LZW compression invented and written up in IEEE Computer
1985 - LZW patent approved
1986 - Sperry (patent holder) merged with Burroughs to form Unisys, not
quite a purchase like I remembered
1987 - CompuServe creates GIF
1993 - Unisys becomes aware that GIF uses LZW compression
This paraphrased from Encyclopedia of Graphics File Formats, 2nd ed.
-Mark Gordn
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Mark Gordon wrote in message <39421BB5.AB8BA839@mailbag.com>...
>Digging out books...
>
>1984 - LZW compression invented and written up in IEEE Computer
>1985 - LZW patent approved
>1986 - Sperry (patent holder) merged with Burroughs to form Unisys, not
>quite a purchase like I remembered
>1987 - CompuServe creates GIF
>1993 - Unisys becomes aware that GIF uses LZW compression
Good news! If the dates here are correct, the patent on LZW will expire in
two years.
Mark
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"Mark Wagner" <mar### [at] gtenet> wrote in message
news:394313ef@news.povray.org...
>
> Mark Gordon wrote in message <39421BB5.AB8BA839@mailbag.com>...
> >Digging out books...
> >
> >1984 - LZW compression invented and written up in IEEE Computer
> >1985 - LZW patent approved
> >1986 - Sperry (patent holder) merged with Burroughs to form Unisys, not
> >quite a purchase like I remembered
> >1987 - CompuServe creates GIF
> >1993 - Unisys becomes aware that GIF uses LZW compression
>
>
> Good news! If the dates here are correct, the patent on LZW will expire
in
> two years.
What I do not understand:
When LZW was published 1984,
how can it be patented in 1985?
I mean as soon as I publish an idea in a newspaper,
it's not any more possible to patent it,
because the idea is general knowledge because
was published before
--
Clear targets for a confused civilization
http://www.BeingFound.com
web design and seminars
+43 699 17343674
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Many thanks for that Mark. I think my memory need replacing :)
Alf
Mark Gordon <mtg### [at] mailbagcom> wrote in message
news:39421BB5.AB8BA839@mailbag.com...
> Alf Peake wrote:
> >
> > When this HooHa started I was under the impression that the
algorithm
> > was patented _after_ CS produced the GIF format but before Unisys
was
> > involved. I was wrong?
>
> Digging out books...
>
> 1984 - LZW compression invented and written up in IEEE Computer
> 1985 - LZW patent approved
> 1986 - Sperry (patent holder) merged with Burroughs to form Unisys,
not
> quite a purchase like I remembered
> 1987 - CompuServe creates GIF
> 1993 - Unisys becomes aware that GIF uses LZW compression
>
> This paraphrased from Encyclopedia of Graphics File Formats, 2nd ed.
>
> -Mark Gordn
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: What I do not understand:
: When LZW was published 1984,
: how can it be patented in 1985?
The patent was approved in 1985. It doesn't mean that the patent application
was made in 1985. The approval of a patent is always a very long process.
--
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/
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>"Mark Wagner" <mar### [at] gtenet> wrote in message
>news:394313ef@news.povray.org...
>>
>> Mark Gordon wrote in message <39421BB5.AB8BA839@mailbag.com>...
>> >1984 - LZW compression invented and written up in IEEE Computer
>> >1985 - LZW patent approved
>
>What I do not understand:
>
>When LZW was published 1984,
>how can it be patented in 1985?
>
>I mean as soon as I publish an idea in a newspaper,
>it's not any more possible to patent it,
>because the idea is general knowledge because
>was published before
That's not quite correct. The "prior art" rule prevents people from
patenting things which they did not invent themselves (otherwise
somebody might patent the wheel and then sue all the car manufacturers).
If you invent something, you can certainly show it or describe it to any
number of people and still patent it. However, it might be somewhat
difficult to prove that you are the inventor, if you show it to too many
people. As other people already pointed out, it takes some time to
approve a patent (if fact, 1 year seems to be remarkably short!).
However, I don't understand something else: When the issue first came up
in 1993, everybody seemed to think that only the compression algorithm
was covered by the patent, not the decompression (That's why gzip can
read .Z-files, but cannot create them). However, the patent cited here
very clearly mentions decompression, too. Are there two patents about
LZW?
hp
--
_ | Peter J. Holzer | Nicht an Tueren mangelt es,
|_|_) | Sysadmin WSR | sondern an der Einrichtung (aka Content).
| | | hjp### [at] wsracat | -- Ale### [at] univieacat
__/ | http://www.hjp.at/ | zum Thema Portale in at.linux
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Wasn't it Peter J. Holzer who wrote:
>>"Mark Wagner" <mar### [at] gtenet> wrote in message
>>news:394313ef@news.povray.org...
>>>
>>> Mark Gordon wrote in message <39421BB5.AB8BA839@mailbag.com>...
>>> >1984 - LZW compression invented and written up in IEEE Computer
>>> >1985 - LZW patent approved
>>
>>What I do not understand:
>>
>>When LZW was published 1984,
>>how can it be patented in 1985?
>>
>>I mean as soon as I publish an idea in a newspaper,
>>it's not any more possible to patent it,
>>because the idea is general knowledge because
>>was published before
>
>That's not quite correct. The "prior art" rule prevents people from
>patenting things which they did not invent themselves (otherwise
>somebody might patent the wheel and then sue all the car manufacturers).
>If you invent something, you can certainly show it or describe it to any
>number of people and still patent it. However, it might be somewhat
>difficult to prove that you are the inventor, if you show it to too many
>people. As other people already pointed out, it takes some time to
>approve a patent (if fact, 1 year seems to be remarkably short!).
I don't think that "prior art" is the rule in question here. If you
publish details of your invention and then later apply for a patent,
that patent is not going to retrospectively protect you from people
using what you have already published.
>However, I don't understand something else: When the issue first came up
>in 1993, everybody seemed to think that only the compression algorithm
>was covered by the patent, not the decompression (That's why gzip can
>read .Z-files, but cannot create them). However, the patent cited here
>very clearly mentions decompression, too. Are there two patents about
>LZW?
The owners of the patent wanted people to freely implement decompression
routines. The basic idea being that this would generate a huge user base
of people who had software that could read the files, but anyone who
wanted to create files to distribute to those users would use software
which was licensed to use the compression algorithm.
--
Mike Williams
Gentleman of Leisure
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"Mike Williams" <mik### [at] nospamplease> wrote in message
news:My4### [at] econymdemoncouk...
> Wasn't it Peter J. Holzer who wrote:
> >>"Mark Wagner" <mar### [at] gtenet> wrote in message
> >>news:394313ef@news.povray.org...
> >>>
> >>> Mark Gordon wrote in message <39421BB5.AB8BA839@mailbag.com>...
> >>> >1984 - LZW compression invented and written up in IEEE Computer
> >>> >1985 - LZW patent approved
> >>
> >>What I do not understand:
> >>
> >>When LZW was published 1984,
> >>how can it be patented in 1985?
> >>
> >>I mean as soon as I publish an idea in a newspaper,
> >>it's not any more possible to patent it,
> >>because the idea is general knowledge because
> >>was published before
> >
> >That's not quite correct. The "prior art" rule prevents people from
> >patenting things which they did not invent themselves (otherwise
> >somebody might patent the wheel and then sue all the car manufacturers).
> >If you invent something, you can certainly show it or describe it to any
> >number of people and still patent it. However, it might be somewhat
> >difficult to prove that you are the inventor, if you show it to too many
> >people. As other people already pointed out, it takes some time to
> >approve a patent (if fact, 1 year seems to be remarkably short!).
>
> I don't think that "prior art" is the rule in question here. If you
> publish details of your invention and then later apply for a patent,
If You publish something in a newspaper,
it's not possible to have a patent later.
Because publishing it makes it general knowledge.
There was once the application for a patent to raise
sunken ships by blowing styrofoam balls into it.
The application was turned down, because it was
public knowledge to do so.
In the 50ties, it was published in a Mickey Mouse
that Donald Duck has raised a sunken ship by
blowing tennis balls into it.
--
Clear targets for a confused civilization
http://www.BeingFound.com
web design and seminars
+43 699 17343674
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>If You publish something in a newspaper,
>it's not possible to have a patent later.
>Because publishing it makes it general knowledge.
35 USC 10 sec. 102:
A person shall be entitled to a patent unless -
(b) the invention was patented or described in a printed publication
in this or a foreign country or in public use or on sale in this
country, more than one year prior to the date of the application
for patent in the United States, or
--
Ron Parker http://www2.fwi.com/~parkerr/traces.html
My opinions. Mine. Not anyone else's.
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