GIF files unsupported?

[Johann Koenig]

When I try to save images as gifs in the GIMP v1.2.3 (for Linux), I get
an error:

Save failed:
/home/jkoenig/temp.gif: Unknown file type.

I looked at my plugins, and saw one GIF entry, but it said it was just
for loading the image. Underneath it are two GIH entries, one for
loading and one for saving. I looked at the plugins that were registerd
with GIMP, but found none for saving an image as a GIF. Ditherize looked
like it might do something, but doesnt say anything about saving as GIF.
Is there a plugin that I am missing, or does the GIMP not support GIFs?
--
-johann koenig

[Helge Hielscher]

Yes, GIF is not supported due to licencing issues. Here is a good
explanation in German: http://www.gimp.de/GIMP_FAQ/1033183710.

I would suggest to use PNG instead of GIF.
http://www.libpng.org/pub/png/
http://www.linuxworld.com/linuxworld/lw-1999-09/lw-09-vcontrol_3.html

Regards,
Helge

[Johann Koenig]

Helge Hielscher wrote:
>
> Yes, GIF is not supported due to licencing issues. Here is a good
> explanation in German: http://www.gimp.de/GIMP_FAQ/1033183710.
>

I realize my name is quite German, unfortunatly I have never learned to
speak/read/write the language. I still have some time to do so though,
and hope to. As for the article, Ill just have to deal with a Google
translation. Thank you for the information.

--
-johann koenig

[Michael Schumacher]

You may also go directly to the sources I've used to gather the
information in my article:

http://www.gimp.org/~tml/gimp/win32/ - 'No GIFs? section
Explaining that and why Gimp can't include GIFs in its standard
installer. There is a separate lzw setup available at
http://www2.arnes.si/~sopjsimo/gimp/.

http://burnallgifs.org/ - linked from the site above
Tons of information about Unisys' patent on LZW, plus some other
questionable patents and patent claims.

HTH,
Michael

[Phuoc Can HUA]

I just can't understand how GIF became such popular? (maybe just like
Windows, many unlicenced users). Does that mean I have to pay $5000 because
I've got some GIF images on my web site? Unfortunately, normal browser
installation only supports GIF and JPEG :-(

I encountered the same problem when I was thinking to use GIF format in my
own program. Luckly there was someone who advised me the Unisys patent.
Otherwise I will be in deep trouble when I try to sell my program one day.
I think we have to make everyone aware of that stupid patent and make other
format more popular. Therefore your suggestion is really good.

Phuoc Can HUA

"Helge Hielscher" <hhiel...@unternehmen.com> wrote in message
news:av7ksh$asa$07$1...@news.t-online.com...

[Olivier Ripoll]

Phuoc Can HUA wrote:

> I just can't understand how GIF became such popular?

There were not that many format at this time. It was compressed, and if you take
into account the fact that the VGA displays could not do more than 256 colours,
it was considered as a lossless compression (which is sometimes still said,
erroneously)
It was free (as free beer, at this time), and could support transparency (a
window is transparent, can be partially colored ; a hole in a wall is not
transparent, it's just a hole, it's a binary state ; thus GIF is not
transparent, but you can make hole in it).

So actually, popularity of GIF is due to 3 misunderstandings (or marketing lies)

- transparency, when it's only a hole capability
- free (beer), which was just for a limited amount of time
- lossless compression, if you have 256 colours or less

> (maybe just like
> Windows, many unlicenced users). Does that mean I have to pay $5000 because
> I've got some GIF images on my web site?

No. The licence says that these 5000 dollars are for the people who develop the
software. This is more a pain for the freeware developers.

> Unfortunately, normal browser
> installation only supports GIF and JPEG :-(

No no no no no.
All browsers installation support PNG.
Transparency, a feature of PNG that GIF does not have, is moreover supported by
*Opera 6+
*Konqueror 3+ and its son Safari for MacOS
*Mozilla since 0.9.x and its sons:
- Netscape 6+
- Phoenix (I don't know its new name) for Win, Linux, MacOS
- Galeon, Skipstone, Epiphany in Unices
- Kmeleon in Windows
*Amaya (I'm not sure, but I think)
*Internet Explorer for MacOS since 4.0 IE Mac was actually the very first
browser to support alpha transparency.

Only two browsers can display PNG but cannot display transparency:
*Nestcape 4 and < (PNG displayed since 4.03 or 4.04) No one is using it anymore
(well, I do, but only for mail and news, not for browsing ;) )
*Internet Explorer for Windows. A painful and heavy trick exists for making it
work.
http://support.microsoft.com/default.aspx?scid=kb;en-us;Q294714
However, IE Win supports binary transparency for indexed PNG (the hole in the
wall ;) )

Many other features of PNG are not supported by many browsers (like gamma
correction) but the formats like GIF do not provide them anyway.

So the status of PNG is:
- At least as good as gif for any non-animated purpose
- Much better than GIF for anything else, and working with most of the browsers

The real two reasons to avoid GIF are:
- technically, it is severely outdated
- it is not free (as in speech)

> I encountered the same problem when I was thinking to use GIF format in my
> own program. Luckly there was someone who advised me the Unisys patent.
> Otherwise I will be in deep trouble when I try to sell my program one day.

You will.

> I think we have to make everyone aware of that stupid patent and make other
> format more popular. Therefore your suggestion is really good.
>
> Phuoc Can HUA
>

Regards,

Olivier.