Zip Magic can do it.
Anyway, if someone is curious and doesn't know of it yet Zip Magic is at
www.mijenix.com
Not only programs in Windows but DOS utilities can see the zip "folder" as
well.  Just made a quick check and it was about a 5 times difference from
uncompressed tga files and pretty much a unnoticeable background occurance.
I don't need to save disk space at the moment but if I ever do this will do
fine I believe.

Bob

"Ken" <tyl### [at] pacbellnet> wrote in message
news:385862C6.C5CC87EA@pacbell.net...
>
>
> Mark Gordon wrote:
>
> > POV-Ray also uses (as part of PNG support) zlib, which includes
> > functions that provide support for GNU zipped files.  The gzip manual
> > page says that gzip and PKZip both use Lempel-Ziv rather than LZW, so
> > that should be completely clear of problems.
> >
> > That handles feasibility.  So, how useful do people think such a thing
> > would be?
> >
> > -Mark Gordon
>
> I know one suggestion comes up from time to time and that is the ability
> to zip image files on the fly for animation work. This is especialy true
> for file types like .tga and .bmp which do not offer built in compression
> methods. I have heard a couple of people mention that this can already
> be done with shell commands but it would be nice if it was done internaly
> to reduce cycle times during high frame count animations.
>
> --
> Wishing you Seasons Greetings, A Merry Christmas, and A Happy New Year !

Post a reply to this message

Mark Gordon wrote:

> POV-Ray already uses LZW (support for GIF's as heightfields).  I'm not
> sure we have a written agreement with Unisys, since that feature
> predates my joining the team.  I'll ask.  If it becomes a serious
> problem, we also support PNG heightfields.

Unisys' claims are fairly extensive, but many in the field believe that their
patent only applies to creation, not to using. Thus, viewing GIF might be fine
even though you need a license from them to create them. Of course, if you
belonged to a large company with some decent pockets you could actually test
this in court. Just because you are right, doesn't mean it would be cheap :-(

(Remember, I am not a lawyer. Consult your attourney for actual advice)

--
"My new computer's got the clocks, it rocks
But it was obsolete before I opened the box" - W.A.Y.

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[On Wed, 15 Dec 1999 21:49:26 -0500, Steve Martin <sma### [at] usitnet>]
| I don't know if there are any license restrictions on the zip format
| (which, I believe, was invented by PKWare in their PKZip product).
| However, if PKZip (and the zip file format) uses LZW compression,

It doesn't. Further more: The zip format has been supported in libz
for quite a while now, and POV-Ray already uses that.

-- 
A penny for your thoughts.
Mine are more expensive.

Post a reply to this message

> Unisys' claims are fairly extensive, but many in the field believe that their
> patent only applies to creation, not to using. Thus, viewing GIF might be fine
> even though you need a license from them to create them.

That was always my understanding, too. However, if you read their web
site
statement carefully, it gives rise to doubt. Here's an excerpt:

  "In all cases, a written license agreement or statement signed by
  an authorized Unisys representative is required from Unisys for
  all use, sale or distribution of any software (including so-called
 "freeware") and/or hardware providing LZW conversion capability
 (for example, downloaded software used for creating/displaying GIF
images)."

This would seem to indicate that Unisys expects one to get a license to
use any piece of software that displays GIFs. That would include every
Netscape and Internet Explorer user as well as the guy who buys and
uses Adobe Photoshop and the like. How about the GIMP project? Do they
have a license from Unisys? How about the users of GIMP? Do they need
one?

One would think that the developer of a piece of software would be
responsible for getting the license, and that the user wouldn't be
required to do so. However, this is also addressed by the Unisys
statement:

  "Microsoft Corporation obtained a license under the above Unisys LZW
  patents in September, 1996. Microsoft's license does NOT extend to
  software developers or third parties who use Microsoft toolkit,
language,
  development or operating system products to provide GIF read/write
and/or
  any other LZW capabilities in their own products (e.g., by way of DLLs
and
  APIs). The complete statement by Microsoft can be found at Microsoft's
  developer-oriented Web site at
http://www.microsoft.com/DEVONLY/Unisys.htm.
  Software developers and third parties who wish to include Microsoft
toolkit,
  language, development or operating system products in their own
products for
  providing GIF or any other LZW capability should contact Unisys for a
  license as instructed below. "

The way this reads, even though Microsoft got a license to implement
DLLs
that provide LZW services, the developer who uses Microsoft's pre-built
DLLs in their projects are *not* covered.

It seems to me that this whole thing is an attempt on the part of some
lawyers
at Unisys to cash in on the Web, to the detriment of its users. Reminds
me of
the guy who went to the US Trademark office and registered himself a
trademark
on the term "Linux". He then went to everyone who was using the term
(book
publishers, software retailers, outfits like Red Hat and Debian, and so
forth) and tried to extort license fees from them for the use of his
"proprietary trademark". He was unjustified, of course, and finally
(under pressure from lawyers and several others) relinquished
his rights to the term "Linux".

Post a reply to this message

On Wed, 15 Dec 1999 20:13:08 -0500, Chris Huff
<chr### [at] yahoocom> wrote:

>
>Hmn, would it be useful or feasible to allow POV to read .zip files 
>directly? Are there any license restrictions on .zip compression, or any 
>other reason this wouldn't be done?

Well, I didn't think on that theme, because as Infozip Zip programs
are free, it has been ported to more platforms than Povray
(unbelieable but true ;-)) and than in the Infozip's copying info file
(http://www.cdrom.com/pub/infozip/doc/COPYING) they say there are not
problems with using the sources (including commercial ones), it seems
an easier approximation to a 'binary' povray scene file.

I am aware than Unisys turned a bit more money-hungry recently with
the lzw theme, but AFAIK it's over commercial application which write
lzw compressed files. 

If that idea is not possible, what about a .tgz file? ;-)

(Sorry but I'm used to read more than to write in english.)

Post a reply to this message

I don't think that a patent made in the US is valid here in Finland
(moreover it's not possible to patent such a thing here even if one wanted
to; there are two reasons for this, the most important one being that you
can't patent previously published things).
  I have made a gif-viewer myself. They can sue me if they want.

-- 
main(i,_){for(_?--i,main(i+2,"FhhQHFIJD|FQTITFN]zRFHhhTBFHhhTBFysdB"[i]
):5;i&&_>1;printf("%s",_-70?_&1?"[]":" ":(_=0,"\n")),_/=2);} /*- Warp -*/

Post a reply to this message

Nieminen Juha wrote:
> 
>   I don't think that a patent made in the US is valid here in Finland
> (moreover it's not possible to patent such a thing here even if one wanted
> to; there are two reasons for this, the most important one being that you
> can't patent previously published things).
>   I have made a gif-viewer myself. They can sue me if they want.

If your country honors international patent agreements, like many civilized
countries do, there is a good chance that patents originated here will apply
in your country too. If you want links to resources of information on patent
and copyright law let me know and I will fill your email box with them :)

-- 
Wishing you Seasons Greetings, A Merry Christmas, and A Happy New Year !

Post a reply to this message

Ken wrote:
> 
> Nieminen Juha wrote:
> >
> >   I don't think that a patent made in the US is valid here in Finland
> > (moreover it's not possible to patent such a thing here even if one wanted
> > to; there are two reasons for this, the most important one being that you
> > can't patent previously published things).
> >   I have made a gif-viewer myself. They can sue me if they want.
> 
> If your country honors international patent agreements, like many civilized
> countries do, there is a good chance that patents originated here will apply
> in your country too. If you want links to resources of information on patent
> and copyright law let me know and I will fill your email box with them :)
> 
> --
> Wishing you Seasons Greetings, A Merry Christmas, and A Happy New Year !


Ken, you are absolutely right! The european community honors the patents
for LZW (even if I don't understand how two independent patents are
possible for the same thing, namely for IBM and UNISYS). In fact it
could be quit dangerous to ignore these patents.
On the other hand you can't get a patent for software as european patent
but as a world patent (which the europeans 
honor).
I'm no lawyer so this is what I know from the patent lectures I heard a
few years ago.

For more on the LZW patent and a way around them see 

http://burnallgifs.org/


All the best,

Marc

-- 
Marc Schimmler

Post a reply to this message

Nieminen Juha wrote:
> 
>   I don't think that a patent made in the US is valid here in Finland
> (moreover it's not possible to patent such a thing here even if one wanted
> to; there are two reasons for this, the most important one being that you
> can't patent previously published things).
	They didn't patent something that was previously published, they just
waited until it was firmly established before trying to enforce their
patent (which AFAIK makes it unenforceable at least in France, but I'm
not a lawyer...)

		Jerome
-- 
*******************************

* they'll tell you what can't * mailto:ber### [at] inamecom
* be done and why...          * http://www.enst.fr/~jberger
* Then do it.                 *
*******************************

Post a reply to this message

>   I have made a gif-viewer myself. They can sue me if they want.

I put a freeware windows based GIF to PNG converter online about
2 years ago, and I still havn't heard from Unisys.  It simply
decodes GIF and encodes PNG - surely a violation of Unisys's vague
patent claims.  I did talk to Unisys about a license, but didn't
feel that a US$500 starting fee was very "community minded".  
(When Unisys jump on the Open Source bandwagon, they'll have a 
lot of back-peddling to do.)

I'd like to know how much Unisys bribed Netscape and Microsoft 
for their poor adoption of PNG in web browsing products.  GIF
is such an outdated hack of a file format that there is no logic
to it's continued popularity.

--
Nigel Stewart (nig### [at] nigelscom)
Research Student, Software Developer, Tokyo Dweller
"The Australian Government wants to censor your email."

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