GIF Format Issues

[imap at chesapeake.net]

Hey, Id sure like to preserve the ability to generate .GIF images
just like they are, but have the option of switching to .PNG or .JPG
or non-LWZ GIF if Unisys comes up with their hands out.  The .PNG change 
looks like a 1 liner, but compiling in both the old and new GD should 
prove to be a challenge.  As I recall, the uncompressed GIF images from 
GD 1.3 were huge.  

-Chris Stuber (imap at chesapeake.net)

Stephen Lime wrote:
> 
> For some reason the GD pulled the non-LZW GIF code from GD 1.6 etc.
> Don't know why. It may be nice way to provide PNG and GIF. ImageMagick
> also has a non-LZW GIF encoder. Grzegorz: any feel for increase in size?
> 
> Steve
> 
> Stephen Lime
> Internet Applications Analyst
> MIS Bureau - MN DNR
> 
> (651) 297-2937
> steve.lime at dnr.state.mn.us
> 
> >>> "Grzegorz Myrda" <mapadm at polsl.gliwice.pl> 09/05 2:44 PM >>>
> I have gd 1.3 which uses non-LZW compression. However mapserv probably needs
> a little correction because there were some disturbances in the image after
> simple exchanging all gd files to version 1.3 files.
> 
> >From the gd doc:
> ...
>      Non-LZW-based GIF compression code.
>           Version 1.3 contains GIF compression code that uses simple Run
>           Length Encoding instead of LZW compression, while still
>           retaining compatibility with normal LZW-based GIF decoders
>           (your browser will still like your GIFs).
> ...
> 
> The different is in the size of output GIF.
> 
> Grzegorz
> 
> > -----Oryginalna wiadomo*æ-----
> > Od: owner-mapserver-users at lists.gis.umn.edu
> > [mailto:owner-mapserver-users at lists.gis.umn.edu]W imieniu Stephen Lime
> > Wys³ano: 31 sierpnia 1999 18:46
> > Do: mapserver-users at lists.gis.umn.edu
> > Temat: GIF Format Issues
> >
> >
> > Greetings: At sometime in the near future a switch from LZW GIF
> > to something
> > else, PNG, JPEG or non-LZW GIF will be necessary. Unisys, the LZW patent
> > holder, requires that software using it's compression technology
> > be licensed. GD,
> > the free GIF graphics library used within the MapServer uses LZW. GD was
> > written well before all of these legal happenings and it's
> > unclear what Unisys' stance
> > on older software is. New versions of GD support PNG only so it's
> > clear how those
> > authors feel.
> >
> > To make MapServer useful as OpenSource the reliance on LZW to end. GD 2.0
> > looks very promising with support for PNG (up to 24bit), JPG and
> > hopefully a non-LZW
> > GIF format, but I've seen no timetable for a 2.0 release.
> >
> > Anyone got any comments or ideas?
> >
> > Steve
> >
> >
> > Stephen Lime
> > Internet Applications Analyst
> > MIS Bureau - MN DNR
> >
> > (651) 297-2937
> > steve.lime at dnr.state.mn.us
> >
> >