glfs/general/graphlib/libungif/libungif-intro.xml

<sect2>
<title>Introduction to <application>libungif</application></title>

<para>The libungif package contains libraries for reading all
<acronym>GIF</acronym>s and writing non-compressed ones as well as programs for 
converting and working with <acronym>GIF</acronym> files.  The libraries are 
useful for any graphics program wishing to deal with <acronym>GIF</acronym> 
files while the programs are useful for conversion purposes as well as cleaning 
up images.</para>

<para>The reason libungif only writes non-compressed <acronym>GIF</acronym>s 
is due to a legal issue with <acronym>LZW</acronym> compression (which Unisys 
claims a patent on). Reading <acronym>GIF</acronym>s is not a problem as the 
decompression routines do not seem to be limited in this way.  Note that this 
has in the past been disputed.  The best way to avoid this whole mess is to 
simply use libungif for looking at <acronym>GIF</acronym> images on the web, 
while in any pages which you design, use the open source <acronym>PNG</acronym> 
format instead (which uses, not surprisingly, the libpng library) which has no 
patent issues at all.</para>

<sect3><title>Package information</title>
<itemizedlist spacing='compact'>
<listitem><para>Download (HTTP): <ulink url="&libungif-download-http;"/></para></listitem>
<listitem><para>Download (FTP): <ulink url="&libungif-download-ftp;"/></para></listitem>
<listitem><para>Download size: &libungif-size;</para></listitem>
<listitem><para>Estimated Disk space required: &libungif-buildsize;</para></listitem>
<listitem><para>Estimated build time: &libungif-time;</para></listitem></itemizedlist>
</sect3>

<sect3><title>Additional downloads</title>
<itemizedlist spacing='compact'>
<listitem><para>Required patch: <ulink
url="&patch-root;/libungif-4.1.0b1-va_start.patch"/></para></listitem>
</itemizedlist>
</sect3>

</sect2>