GIF Format Issues

[Grzegorz Myrda]

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 wiadomoϾ-----
> 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
>
>