Re: GIF again.....

[Jeff Guerber <jguerber(at)icesat2.gsfc.nasa.gov>]

Dick,

    xv's current home is http://www.trilon.com/xv/.  I seem to recall
seeing something there (although I can't find it now) indicating that GIF
licensing is the reason there hasn't been a complete, new version of xv
since 3.10a in 1994!  (I am not a lawyer, so I'll refrain from taking this
any further.  Actually, I always thought that it was only _writing_ GIFs
that was illegal; but, as I said, IANAL.)  We're looking into working
around the lack of GIF support in IDL by using PNG (which was developed by
the W3C itself) instead :-).

    (The Web site does have a number of patches you can apply to the 3.10a
sources; my system manager recently rebuilt our copy with the patches, and
they seem to work great.  Not that it helps for what you want to do.)

    Usual disclamers apply: IANAL, I don't speak for NASA or Raytheon,
etc. etc.
                                                    Jeff Guerber

On Fri, 5 Jan 2001, Richard G. French wrote:

> After 5.4 came out, there were a lot of posts about the disappearance
> of the GIF writer and reader routines. Can any of you experts tell me
> about the legality of using shareware C code that reads and writes 
> GIF files, originally used as part of the XV program that displays
> lots of image types on UNIX boxes? The idea would be to write  
> wrapper routines that could call WriteGIF and ReadGIF in the XV
> code so that GIF writing and reading could be restored in IDL.
> 
> These routines are in the pub/xv subdirectory of
> ftp.cis.upenn.edu
> 
> 	If this is not legal, does it mean that XV is not legal,
> either, even if you pay the registration fee?
> 
> 	Has anyone come up with a legal scheme under UNIX to
> read and write GIF files? If you have to pay a license fee, does
> anyone know what the fee would be for a single user?
> 	Thanks for any hints on workarounds.
> Dick French