   #PHP Manual Image functions exif_imagetype exif_thumbnail

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                                exif_read_data

   (PHP 4 >= 4.2.0)
   exif_read_data -- Reads the EXIF headers from JPEG or TIFF. This way
   you can read meta data generated by digital cameras.

Description

   array exif_read_data ( string filename [, string sections [, bool
   arrays [, bool thumbnail]]])

   The exif_read_data() function reads the EXIF headers from a JPEG or
   TIFF image file. It returns an associative array where the indexes are
   the header names and the values are the values associated with those
   headers. If no data can be returned the result is FALSE.

   filename is the name of the file to read. This cannot be an url.

   sections is a comma separated list of sections that need to be present
   in file to produce a result array. If none of the requested sections
   could be found the return value is FALSE.

   FILE FileName, FileSize, FileDateTime, SectionsFound
   COMPUTED html, Width, Height, IsColor and some more if available.
   ANY_TAG Any information that has a Tag e.g. IFD0, EXIF, ...
   IFD0 All tagged data of IFD0. In normal imagefiles this contains image
   size and so forth.
   THUMBNAIL A file is supposed to contain a thumbnail if it has a second
   IFD. All tagged information about the embedded thumbnail is stored in
   this section.
   COMMENT Comment headers of JPEG images.
   EXIF The EXIF section is a sub section of IFD0. It contains more
   detailed information about an image. Most of these entries are digital
   camera related.

   arrays specifies whether or not each section becomes an array. The
   sections COMPUTED, THUMBNAIL and COMMENT allways become arrays as they
   may contain values whose names are conflict with other sections.

   thumbnail whether or not to read the thumbnail itself and not only its
   tagged data.

     Note: Exif 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.

     Windows ME/XP both can wipe the Exif headers when connecting to a
     camera. More information available at
     http://ww2.canon-europe.com/products/cameras/notices_dig_cam_users.
     html.

   Example 1. exif_read_data() example
   <?php
   echo "test1.jpg:<br />\n";
   $exif = exif_read_data('tests/test1.jpg', 'IFD0');
   echo $exif===false ? "No header data found.<br />\n" : "Image contains
   headers<br />";
   $exif = exif_read_data('tests/test2.jpg', 0, true);
   echo "test2.jpg:<br />\n";
   foreach ($exif as $key => $section) {
       foreach ($section as $name => $val) {
           echo "$key.$name: $val<br />\n";
       }
   }
   ?>

   The first call fails because the image has no header information.
   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

     Note: If the image contains any IFD0 data then COMPUTED contains
     the entry ByteOrderMotorola which is 0 for little-endian (intel)
     and 1 for big-endian (motorola) byte order. This was added in PHP
     4.3.

     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 COMPUTED section will return both entries
     Copyright.Photographer and Copyright.Editor while the IFD0 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 COMPUTED will contain also an entry
     Copyright Which is either the original copyright string or it is a
     comma separated list of photo and editor copyright.

     Note: The tag UserComment 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 IFD section only contains the encoding or a
     byte array. The COMPUTED section will store both in the entries
     UserCommentEncoding and UserComment. The entry UserComment is
     available in both cases so it should be used in preference to the
     value in IFD0 section.

     If the user comment uses Unicode or JIS encoding and the module
     mbstring is available this encoding will automatically changed
     according to the exif ini settings in the php.ini. This was added
     in PHP 4.3.

     Note: Height and Width are computed the same way getimagesize()
     does so their values must not be part of any header returned. Also
     html is a height/width text string to be used inside normal HTML.

     Note: Starting from PHP 4.3 the function can read all embedded IFD
     data including arrays (returned as such). Also the size of an
     embedded thumbnail is returned in THUMBNAIL subarray and the
     function exif_read_data() can return thumbnails in TIFF format.
     Last but not least there is no longer a maximum length for returned
     values (not until memory limit is reached).

     Note: This function is only available in PHP 4 compiled using
     --enable-exif. Its functionality and behaviour has changed in PHP
     4.2. Earlier versions are very unstable.

     Since PHP 4.3 user comment can automatically change encoding if PHP
     4 was compiled using --enable-mbstring.

     This function does not require the GD image library.

     See also exif_thumbnail() and getimagesize().
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