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<title>Reads the EXIF headers from JPEG or TIFF</title>
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<h1 class="refname">exif_read_data</h1>
<p class="verinfo">(PHP 4 >= 4.2.0, PHP 5)</p><p class="refpurpose"><span class="refname">exif_read_data</span> — <span class="dc-title">Reads the <acronym title="Exchangeable Image File ">EXIF</acronym> headers from <acronym title="Joint Photographic Experts Group">JPEG</acronym> or <acronym title="Tagged Image File Format">TIFF</acronym></span></p>
</div>
<div class="refsect1 description" id="refsect1-function.exif-read-data-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">array</span> <span class="methodname"><strong>exif_read_data</strong></span>
( <span class="methodparam"><span class="type">string</span> <code class="parameter">$filename</code></span>
[, <span class="methodparam"><span class="type">string</span> <code class="parameter">$sections</code><span class="initializer"> = <strong><code>NULL</code></strong></span></span>
[, <span class="methodparam"><span class="type">bool</span> <code class="parameter">$arrays</code><span class="initializer"> = false</span></span>
[, <span class="methodparam"><span class="type">bool</span> <code class="parameter">$thumbnail</code><span class="initializer"> = false</span></span>
]]] )</div>
<p class="para rdfs-comment">
<span class="function"><strong>exif_read_data()</strong></span> reads the
<acronym title="Exchangeable Image File ">EXIF</acronym> headers from a <acronym title="Joint Photographic Experts Group">JPEG</acronym> or
<acronym title="Tagged Image File Format">TIFF</acronym> image file. This way you can read meta data
generated by digital cameras.
</p>
<p class="para">
<acronym title="Exchangeable Image File ">EXIF</acronym> headers tend to be present in JPEG/TIFF images generated by digital
cameras, but unfortunately each digital camera maker has a different
idea of how to actually tag their images, so you can't always rely on
a specific Exif header being present.
</p>
<p class="para">
<em>Height</em> and <em>Width</em> are computed the
same way <span class="function"><a href="function.getimagesize.html" class="function">getimagesize()</a></span> does so their values must not be
part of any header returned. Also, <em>html</em> is a
height/width text string to be used inside normal <acronym title="Hyper Text Markup Language">HTML</acronym>.
</p>
<p class="para">
When an Exif header contains a Copyright note, this itself can contain two
values. As the solution is inconsistent in the Exif 2.10 standard, the
<em>COMPUTED</em> section will return both entries
<em>Copyright.Photographer</em> and
<em>Copyright.Editor</em> while the <em>IFD0</em>
sections contains the byte array with the NULL character that splits both
entries. Or just the first entry if the datatype was wrong (normal behaviour
of Exif). The <em>COMPUTED</em> will also contain the entry
<em>Copyright</em> which is either the original copyright string,
or a comma separated list of the photo and editor copyright.
</p>
<p class="para">
The tag <em>UserComment</em> has the same problem as the Copyright
tag. It can store two values. First the encoding used, and second the value
itself. If so the <em>IFD</em> section only contains the encoding
or a byte array. The <em>COMPUTED</em> section will store both in
the entries <em>UserCommentEncoding</em> and
<em>UserComment</em>. The entry <em>UserComment</em>
is available in both cases so it should be used in preference to the value
in <em>IFD0</em> section.
</p>
<p class="para">
<span class="function"><strong>exif_read_data()</strong></span> also validates EXIF data tags according
to the EXIF specification (<a href="http://exif.org/Exif2-2.PDF" class="link external">» http://exif.org/Exif2-2.PDF</a>, page 20).
</p>
<blockquote class="note"><p><strong class="note">Note</strong>:
<p class="para">
Windows Me/XP can both wipe the Exif headers when connecting to a camera.
</p>
</p></blockquote>
</div>
<div class="refsect1 parameters" id="refsect1-function.exif-read-data-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<span class="term"><em><code class="parameter">filename</code></em></span>
<dd>
<p class="para">
The name of the image file being read. This cannot be an
<acronym title="Uniform Resource Locator">URL</acronym>.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">sections</code></em></span>
<dd>
<p class="para">
Is a comma separated list of sections that need to be present in file
to produce a result <span class="type"><a href="language.types.array.html" class="type array">array</a></span>. If none of the requested
sections could be found the return value is <strong><code>FALSE</code></strong>.
<table class="doctable informaltable">
<tbody class="tbody">
<tr>
<td>FILE</td>
<td>FileName, FileSize, FileDateTime, SectionsFound</td>
</tr>
<tr>
<td>COMPUTED</td>
<td>
html, Width, Height, IsColor, and more if available. Height and
Width are computed the same way <span class="function"><a href="function.getimagesize.html" class="function">getimagesize()</a></span>
does so their values must not be part of any header returned.
Also, <em>html</em> is a height/width text string to be used inside normal
<acronym title="Hyper Text Markup Language">HTML</acronym>.
</td>
</tr>
<tr>
<td>ANY_TAG</td>
<td>Any information that has a Tag e.g. <em>IFD0</em>, <em>EXIF</em>, ...</td>
</tr>
<tr>
<td>IFD0</td>
<td>
All tagged data of IFD0. In normal imagefiles this contains
image size and so forth.
</td>
</tr>
<tr>
<td>THUMBNAIL</td>
<td>
A file is supposed to contain a thumbnail if it has a second <em>IFD</em>.
All tagged information about the embedded thumbnail is stored in
this section.
</td>
</tr>
<tr>
<td>COMMENT</td>
<td>Comment headers of JPEG images.</td>
</tr>
<tr>
<td>EXIF</td>
<td>
The EXIF section is a sub section of <em>IFD0</em>. It contains
more detailed information about an image. Most of these entries
are digital camera related.
</td>
</tr>
</tbody>
</table>
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">arrays</code></em></span>
<dd>
<p class="para">
Specifies whether or not each section becomes an array. The
<em><code class="parameter">sections</code></em> <em>COMPUTED</em>,
<em>THUMBNAIL</em>, and <em>COMMENT</em>
always become arrays as they may contain values whose names conflict
with other sections.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">thumbnail</code></em></span>
<dd>
<p class="para">
When set to <strong><code>TRUE</code></strong> the thumbnail itself is read. Otherwise, only the
tagged data is read.
</p>
</dd>
</dt>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.exif-read-data-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
It returns an associative <span class="type"><a href="language.types.array.html" class="type array">array</a></span> where the array indexes are
the header names and the array values are the values associated with
those headers. If no data can be returned,
<span class="function"><strong>exif_read_data()</strong></span> will return <strong><code>FALSE</code></strong>.
</p>
</div>
<div class="refsect1 changelog" id="refsect1-function.exif-read-data-changelog">
<h3 class="title">Changelog</h3>
<p class="para">
<table class="doctable informaltable">
<thead>
<tr>
<th>Version</th>
<th>Description</th>
</tr>
</thead>
<tbody class="tbody">
<tr>
<td>4.3.0</td>
<td>
Can read all embedded <acronym title="Image File Directory">IFD</acronym> data including arrays
(returned as such). Also the size of an embedded thumbnail is
returned in a <em>THUMBNAIL</em> subarray, and can
return thumbnails in <acronym title="Tagged Image File Format">TIFF</acronym> format. Also, there is
no longer a maximum length for returned values (not until the memory
limit has been reached)
</td>
</tr>
<tr>
<td>4.3.0</td>
<td>
If PHP has <a href="ref.mbstring.html" class="link">mbstring</a> support,
the user comment can automatically change encoding. Also, if the
user comment uses <em>Unicode</em> or <em>JIS</em> encoding this encoding will
automatically be changed according to the exif ini settings in
<var class="filename">php.ini</var>
</td>
</tr>
<tr>
<td>4.3.0</td>
<td>
If the image contains any <em>IFD0</em> data then
<em>COMPUTED</em> contains the entry
<em>ByteOrderMotorola</em> which is 0 for
<em>little-endian</em> (intel) and 1 for
<em>big-endian</em> (motorola) byte order. Also,
<em>COMPUTED</em> and <em>UserComment</em> no
longer only contain the first copyright entry if the datatype was
wrong.
</td>
</tr>
</tbody>
</table>
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.exif-read-data-examples">
<h3 class="title">Examples</h3>
<p class="para">
<div class="example" id="example-3163">
<p><strong>Example #1 <span class="function"><strong>exif_read_data()</strong></span> example</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /></span><span style="color: #007700">echo </span><span style="color: #DD0000">"test1.jpg:<br />\n"</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$exif </span><span style="color: #007700">= </span><span style="color: #0000BB">exif_read_data</span><span style="color: #007700">(</span><span style="color: #DD0000">'tests/test1.jpg'</span><span style="color: #007700">, </span><span style="color: #DD0000">'IFD0'</span><span style="color: #007700">);<br />echo </span><span style="color: #0000BB">$exif</span><span style="color: #007700">===</span><span style="color: #0000BB">false </span><span style="color: #007700">? </span><span style="color: #DD0000">"No header data found.<br />\n" </span><span style="color: #007700">: </span><span style="color: #DD0000">"Image contains headers<br />\n"</span><span style="color: #007700">;<br /><br /></span><span style="color: #0000BB">$exif </span><span style="color: #007700">= </span><span style="color: #0000BB">exif_read_data</span><span style="color: #007700">(</span><span style="color: #DD0000">'tests/test2.jpg'</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">, </span><span style="color: #0000BB">true</span><span style="color: #007700">);<br />echo </span><span style="color: #DD0000">"test2.jpg:<br />\n"</span><span style="color: #007700">;<br />foreach (</span><span style="color: #0000BB">$exif </span><span style="color: #007700">as </span><span style="color: #0000BB">$key </span><span style="color: #007700">=> </span><span style="color: #0000BB">$section</span><span style="color: #007700">) {<br /> foreach (</span><span style="color: #0000BB">$section </span><span style="color: #007700">as </span><span style="color: #0000BB">$name </span><span style="color: #007700">=> </span><span style="color: #0000BB">$val</span><span style="color: #007700">) {<br /> echo </span><span style="color: #DD0000">"</span><span style="color: #0000BB">$key</span><span style="color: #DD0000">.</span><span style="color: #0000BB">$name</span><span style="color: #DD0000">: </span><span style="color: #0000BB">$val</span><span style="color: #DD0000"><br />\n"</span><span style="color: #007700">;<br /> }<br />}<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
<div class="example-contents"><p>
The first call fails because the image has no header information.
</p></div>
<div class="example-contents"><p>The above example will output
something similar to:</p></div>
<div class="example-contents screen">
<div class="cdata"><pre>
test1.jpg:
No header data found.
test2.jpg:
FILE.FileName: test2.jpg
FILE.FileDateTime: 1017666176
FILE.FileSize: 1240
FILE.FileType: 2
FILE.SectionsFound: ANY_TAG, IFD0, THUMBNAIL, COMMENT
COMPUTED.html: width="1" height="1"
COMPUTED.Height: 1
COMPUTED.Width: 1
COMPUTED.IsColor: 1
COMPUTED.ByteOrderMotorola: 1
COMPUTED.UserComment: Exif test image.
COMPUTED.UserCommentEncoding: ASCII
COMPUTED.Copyright: Photo (c) M.Boerger, Edited by M.Boerger.
COMPUTED.Copyright.Photographer: Photo (c) M.Boerger
COMPUTED.Copyright.Editor: Edited by M.Boerger.
IFD0.Copyright: Photo (c) M.Boerger
IFD0.UserComment: ASCII
THUMBNAIL.JPEGInterchangeFormat: 134
THUMBNAIL.JPEGInterchangeFormatLength: 523
COMMENT.0: Comment #1.
COMMENT.1: Comment #2.
COMMENT.2: Comment #3end
THUMBNAIL.JPEGInterchangeFormat: 134
THUMBNAIL.Thumbnail.Height: 1
THUMBNAIL.Thumbnail.Height: 1
</pre></div>
</div>
</div>
</p>
</div>
<div class="refsect1 seealso" id="refsect1-function.exif-read-data-seealso">
<h3 class="title">See Also</h3>
<p class="para">
<ul class="simplelist">
<li class="member"> <span class="function"><a href="function.exif-thumbnail.html" class="function" rel="rdfs-seeAlso">exif_thumbnail()</a> - Retrieve the embedded thumbnail of a TIFF or JPEG image</span></li>
<li class="member"> <span class="function"><a href="function.getimagesize.html" class="function" rel="rdfs-seeAlso">getimagesize()</a> - Get the size of an image</span></li>
</ul>
</p>
</div>
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