php-doc-en/reference/exif/functions/exif-thumbnail.xml
2017-11-27 10:20:57 +00:00

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<?xml version="1.0" encoding="utf-8"?>
<!-- $Revision$ -->
<!-- splitted from ./en/functions/image.xml, last change in rev 1.78 -->
<refentry xml:id="function.exif-thumbnail" xmlns="http://docbook.org/ns/docbook">
<refnamediv>
<refname>exif_thumbnail</refname>
<refpurpose>Retrieve the embedded thumbnail of an image</refpurpose>
</refnamediv>
<refsect1 role="description">
&reftitle.description;
<methodsynopsis>
<type>string</type><methodname>exif_thumbnail</methodname>
<methodparam><type>mixed</type><parameter>stream</parameter></methodparam>
<methodparam choice="opt"><type>int</type><parameter role="reference">width</parameter></methodparam>
<methodparam choice="opt"><type>int</type><parameter role="reference">height</parameter></methodparam>
<methodparam choice="opt"><type>int</type><parameter role="reference">imagetype</parameter></methodparam>
</methodsynopsis>
<para>
<function>exif_thumbnail</function> reads the embedded thumbnail of an image.
</para>
<para>
If you want to deliver thumbnails through this function, you should send
the mimetype information using the <function>header</function> function.
</para>
<para>
It is possible that <function>exif_thumbnail</function> cannot create an
image but can determine its size. In this case, the return value is
&false; but <parameter>width</parameter> and <parameter>height</parameter>
are set.
</para>
</refsect1>
<refsect1 role="parameters">
&reftitle.parameters;
<para>
<variablelist>
<varlistentry>
<term><parameter>stream</parameter></term>
<listitem>
<para>
The location of the image file. This can either be a path to the file
or a stream <type>resource</type>.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>width</parameter></term>
<listitem>
<para>
The return width of the returned thumbnail.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>height</parameter></term>
<listitem>
<para>
The returned height of the returned thumbnail.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>imagetype</parameter></term>
<listitem>
<para>
The returned image type of the returned thumbnail. This is either
<acronym>TIFF</acronym> or <acronym>JPEG</acronym>.
</para>
</listitem>
</varlistentry>
</variablelist>
</para>
</refsect1>
<refsect1 role="returnvalues">
&reftitle.returnvalues;
<para>
Returns the embedded thumbnail, or &false; if the image contains no
thumbnail.
</para>
</refsect1>
<refsect1 role="examples">
&reftitle.examples;
<para>
<example>
<title><function>exif_thumbnail</function> example</title>
<programlisting role="php">
<![CDATA[
<?php
$image = exif_thumbnail('/path/to/image.jpg', $width, $height, $type);
if ($image!==false) {
header('Content-type: ' .image_type_to_mime_type($type));
echo $image;
exit;
} else {
// no thumbnail available, handle the error here
echo 'No thumbnail available';
}
?>
]]>
</programlisting>
</example>
</para>
</refsect1>
<refsect1 role="changelog">
&reftitle.changelog;
<para>
<informaltable>
<tgroup cols="2">
<thead>
<row>
<entry>&Version;</entry>
<entry>&Description;</entry>
</row>
</thead>
<tbody>
<row>
<entry>7.2.0</entry>
<entry>
The <parameter>filename</parameter> parameter was renamed to
<parameter>stream</parameter> and now supports both local files
or stream resources.
</entry>
</row>
</tbody>
</tgroup>
</informaltable>
</para>
</refsect1>
<refsect1 role="notes">
&reftitle.notes;
<note>
<para>
If the <parameter>stream</parameter> is used to pass a stream to this function, then the stream
must be seekable. Note that the file pointer position is not changed after this function returns.
</para>
</note>
</refsect1>
<refsect1 role="seealso">
&reftitle.seealso;
<para>
<simplelist>
<member><function>exif_read_data</function></member>
<member><function>image_type_to_mime_type</function></member>
</simplelist>
</para>
</refsect1>
</refentry>
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