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<?xml version="1.0" encoding="iso-8859-1"?>
<!-- $Revision: 1.9 $ -->
<!-- splitted from ./en/functions/image.xml, last change in rev 1.3 -->
<refentry id="function.imagegif">
<refnamediv>
<refname>imagegif</refname>
<refpurpose>Output image to browser or file</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<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> 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>
<para>
The filename argument is optional, and if left off, the raw image
stream will be output directly. By sending an image/gif
content-type using <function>header</function>, you can create a
PHP script that outputs <acronym>GIF</acronym> images directly.
<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
<ulink url="&url.gd;">GD Project</ulink> 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 ($im);</literal> by the more flexible sequence:
<informalexample>
<programlisting role="php">
<![CDATA[
<?php
if (function_exists("imagegif")) {
header("Content-type: image/gif");
imagegif($im);
} elseif (function_exists("imagejpeg")) {
header("Content-type: image/jpeg");
imagejpeg($im, "", 0.5);
} elseif (function_exists("imagepng")) {
header("Content-type: image/png");
imagepng($im);
} elseif (function_exists("imagewbmp")) {
header("Content-type: image/vnd.wap.wbmp");
imagewbmp($im);
} else {
die("No image support in this PHP server");
}
?>
]]>
</programlisting>
</informalexample>
</para>
</note>
<note>
<para>
As of version 3.0.18 and 4.0.2 you can use the function
<function>imagetypes</function> in place of
<function>function_exists</function> for checking
the presence of the various supported image formats:
<informalexample>
<programlisting role="php">
<![CDATA[
<?php
if (imagetypes() & IMG_GIF) {
header ("Content-type: image/gif");
imagegif ($im);
} elseif (imagetypes() & IMG_JPG) {
/* ... etc. */
}
?>
]]>
</programlisting>
</informalexample>
</para>
</note>
</para>
<para>
See also <function>imagepng</function>, <function>imagewbmp</function>,
<function>imagejpeg</function> and <function>imagetypes</function>.
</para>
</refsect1>
</refentry>
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