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<?xml version="1.0" encoding="iso-8859-1"?>
<!-- $Revision: 1.19 $ -->
<refentry xml:id="function.imagegif" xmlns="http://docbook.org/ns/docbook" xmlns:xlink="http://www.w3.org/1999/xlink">
<refnamediv>
<refname>imagegif</refname>
<refpurpose>Output image to browser or file</refpurpose>
</refnamediv>
<refsect1 role="description">
&reftitle.description;
<methodsynopsis>
<type>bool</type><methodname>imagegif</methodname>
<methodparam><type>resource</type><parameter>image</parameter></methodparam>
<methodparam choice="opt"><type>string</type><parameter>filename</parameter></methodparam>
</methodsynopsis>
<para>
<function>imagegif</function> creates the <acronym>GIF</acronym>
file in filename from the image <parameter>image</parameter>. The
<parameter>image</parameter> argument is the return from the
<function>imagecreate</function> or <literal>imagecreatefrom*</literal>
function.
</para>
<para>
The image format will be <acronym>GIF87a</acronym> unless the
image has been made transparent with
<function>imagecolortransparent</function>, in which case the
image format will be <acronym>GIF89a</acronym>.
</para>
</refsect1>
<refsect1 role="parameters">
&reftitle.parameters;
<para>
<variablelist>
&gd.image.description;
<varlistentry>
<term><parameter>filename</parameter></term>
<listitem>
<para>
The path to save the file to. If not set or &null;, the raw image stream
will be outputted directly.
</para>
</listitem>
</varlistentry>
</variablelist>
</para>
</refsect1>
<refsect1 role="returnvalues">
&reftitle.returnvalues;
<para>
&return.success;
</para>
</refsect1>
<refsect1 role="examples">
&reftitle.examples;
<para>
<example>
<title>Outputting an image using <function>imagegif</function></title>
<programlisting role="php">
<![CDATA[
<?php
// Create a new image instance
$im = imagecreatetruecolor(100, 100);
// Make the background white
imagefilledrectangle($im, 0, 0, 99, 99, 0xFFFFFF);
// Draw a text string on the image
imagestring($im, 3, 40, 20, 'GD Library', 0xFFBA00);
// Output the image to browser
header('Content-type: image/gif');
imagegif($im);
imagedestroy($im);
?>
]]>
</programlisting>
</example>
<example>
<title>Converting a PNG image to GIF using <function>imagegif</function></title>
<programlisting role="php">
<![CDATA[
<?php
// Load the PNG
$png = imagecreatefrompng('./php.png');
// Save the image as a GIF
imagegif($png, './php.gif');
// Free from memory
imagedestroy($png);
// We're done
echo 'Converted PNG image to GIF with success!';
?>
]]>
</programlisting>
</example>
</para>
</refsect1>
<refsect1 role="notes">
&reftitle.notes;
<note>
<para>
Since all <acronym>GIF</acronym> support was removed from the
<acronym>GD</acronym> library in version 1.6, this function is
not available if you are using that version of the GD library.
Support is expected to return in a version subsequent to the
rerelease of <acronym>GIF</acronym> support in the GD library in
mid 2004. For more information, see the
<link xlink:href="&url.gd;">GD Project</link> site.
</para>
<para>
The following code snippet allows you to write more
portable PHP applications by auto-detecting the
type of GD support which is available. Replace
the sequence <literal>header ("Content-type: image/gif");
imagegif ($im);</literal> by the more flexible sequence:
<informalexample>
<programlisting role="php">
<![CDATA[
<?php
// Create a new image instance
$im = imagecreatetruecolor(100, 100);
// Do some image operations here
// Handle output
if(function_exists('imagegif'))
{
// For GIF
header('Content-type: image/gif');
imagegif($im);
}
elseif(function_exists('imagejpeg'))
{
// For JPEG
header('Content-type: image/jpeg');
imagejpeg($im, NULL, 100);
}
elseif(function_exists('imagepng'))
{
// For PNG
header('Content-type: image/png');
imagepng($im);
}
elseif(function_exists('imagewbmp'))
{
// For WBMP
header('Content-type: image/vnd.wap.wbmp');
imagewbmp($im);
}
else
{
imagedestroy($im);
die('No image support in this PHP server');
}
// If image support was found for one of these
// formats, then free it from memory
if($im)
{
imagedestroy($im);
}
?>
]]>
</programlisting>
</informalexample>
</para>
</note>
<note>
<para>
As of PHP 3.0.18 and 4.0.2 you can use the function
<function>imagetypes</function> in place of
<function>function_exists</function> for checking
the presence of the various supported image formats:
<informalexample>
<programlisting role="php">
<![CDATA[
<?php
if(imagetypes() & IMG_GIF)
{
header('Content-type: image/gif');
imagegif($im);
}
elseif(imagetypes() & IMG_JPG)
{
/* ... etc. */
}
?>
]]>
</programlisting>
</informalexample>
</para>
</note>
</refsect1>
<refsect1 role="seealso">
&reftitle.seealso;
<para>
<simplelist>
<member><function>imagepng</function></member>
<member><function>imagewbmp</function></member>
<member><function>imagejpeg</function></member>
<member><function>imagetypes</function></member>
</simplelist>
</para>
</refsect1>
</refentry>
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