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<!DOCTYPE refentry PUBLIC
   "-//OASIS//DTD DocBook XML V4.1.2//EN"
   "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" []>
<refentry id='gifbg.1'>
<refentryinfo><date>2 May 2012</date></refentryinfo>
<refmeta>
<refentrytitle>gifbg</refentrytitle>
<manvolnum>1</manvolnum>
<refmiscinfo class="source">GIFLIB</refmiscinfo>
<refmiscinfo class="manual">GIFLIB Documentation</refmiscinfo>
</refmeta>
<refnamediv id='name'>
<refname>gifbg</refname>
<refpurpose>generarate a test-pattern GIF</refpurpose>
</refnamediv>

<refsynopsisdiv id='synopsis'>

<cmdsynopsis>
  <command>gifbg</command>
      <arg choice='opt'>-v</arg>
      <arg choice='opt'>-d <replaceable>dir</replaceable></arg>
      <arg choice='opt'>-l <replaceable>lvls</replaceable></arg>
      <arg choice='opt'>-c 
      		<replaceable>R</replaceable>
      		<replaceable>G</replaceable>
      		<replaceable>B</replaceable></arg>
      <arg choice='opt'>-m <replaceable>min</replaceable></arg>
      <arg choice='opt'>-o <replaceable>max</replaceable></arg>
      <arg choice='opt'>-s 
      		<replaceable>w</replaceable>
		<replaceable>h</replaceable></arg>
      <arg choice='opt'>-h</arg>
</cmdsynopsis>
</refsynopsisdiv>

<refsect1><title>Description</title>

<para>A program to generate a single-color test pattern GIF with
gradually changing intensity in any of the basic 8 directions.</para>

<para>The gifbg program reads no input, and will dump the created GIF file
to stdout.</para>

</refsect1>
<refsect1><title>Options</title>

<variablelist>
<varlistentry>
<term>-v</term>
<listitem>
<para> Verbose mode (show progress). 
Enables printout of running scan lines.</para>
</listitem>
</varlistentry>
<varlistentry>
<term>-d dir</term>
<listitem>
<para>Select direction the intensity of the background should
increase. Direction can be one of the 8 principal directions:</para>
<variablelist>
<varlistentry>
<term>"T"</term>
<listitem><para>for Top</para></listitem></varlistentry>
<varlistentry>
<term>"TR"</term>
<listitem><para>for Top Right</para></listitem></varlistentry>
<varlistentry>
<term>"R"</term>
<listitem><para>for Right</para></listitem></varlistentry>
<varlistentry>
<term>"BR"</term>
<listitem><para>for Bottom Right</para></listitem></varlistentry>
<varlistentry>
<term>"B"</term>
<listitem><para>for Bottom</para></listitem></varlistentry>
<varlistentry>
<term>"BL"</term>
<listitem><para>for Bottom Left</para></listitem></varlistentry>
<varlistentry>
<term>"L"</term>
<listitem><para>for left</para></listitem></varlistentry>
<varlistentry>
<term>"TL"</term>
<listitem><para>for Top Left</para></listitem></varlistentry>
</variablelist>
<para>The compass directions may be use as synonyms for the above directions, so
for example "NE" is equal to "TR".</para>
<para>Direction is case insensitive. The default direction is Top
(North).</para>
</listitem>
</varlistentry>
<varlistentry>
<term> -l lvls</term>
<listitem>
<para> Numeric, nmber of levels the color will be scaled to. Default is 16.</para>
</listitem>
</varlistentry>
<varlistentry>
<term> -c R G B</term>
<listitem>
<para> What to use as the primary background color to scale. This
color is scaled between the minimum intensity (min) and maximum
intensity (max) from one end of the screen to the other as defined by
dir.  See below (-m &amp; -M) for min &amp; max. Default is Blue (0,
0, 255).</para>
</listitem>
</varlistentry>
<varlistentry>
<term> -m min</term>
<listitem>
<para> Minimum intensity (in percent) to scale color.  Default 10%</para>
</listitem>
</varlistentry>
<varlistentry>
<term> [-M max</term>
<listitem>
<para> Maximum intensity (in percent) to scale color.  Default 100%</para>
</listitem>
</varlistentry>
<varlistentry>
<term> -s W H</term>
<listitem>
<para> Size of image to create.  Default 640 by 350.</para>
</listitem>
</varlistentry>
<varlistentry>
<term> -h</term>
<listitem>
<para> Print one line of command line help, similar to Usage above.</para>
</listitem>
</varlistentry>
</variablelist>

<para>If min == max = 100 (%) and lvls == 2 then boolean mask image
of specified size will be created - all foreground.  This can be used
as a square mask for the <ulink url="gifcomb.html"></ulink>gifcomb
utility.</para>

</refsect1>
<refsect1><title>Author</title>

<para>Gershon Elber.</para>

</refsect1>
</refentry>
