Updat documentation for exif_read_data

git-svn-id: https://svn.php.net/repository/phpdoc/en/trunk@77937 c90b9560-bf6c-de11-be94-00142212c4b1
This commit is contained in:
Marcus Boerger 2002-04-12 19:46:42 +00:00
parent f59bb0ee20
commit 0f81f5a628

View file

@ -1,5 +1,5 @@
<?xml version="1.0" encoding="iso-8859-1"?>
<!-- $Revision: 1.93 $ -->
<!-- $Revision: 1.94 $ -->
<reference id="ref.image">
<title>Image functions</title>
<titleabbrev>Image</titleabbrev>
@ -126,7 +126,8 @@
</row>
<row>
<entry>COMPUTED</entry>
<entry>html, Width, Height, IsColor and some more if available.</entry>
<entry>html, Width, Height, IsColor and some more if available.
</entry>
</row>
<row>
<entry>ANY_TAG</entry>
@ -145,7 +146,7 @@
</row>
<row>
<entry>COMMENT</entry>
<entry>Cemment headers of JPEG images.</entry>
<entry>Comment headers of JPEG images.</entry>
</row>
<row>
<entry>EXIF</entry>
@ -202,23 +203,27 @@ test1.jpg:
No header data found.
test2.jpg:
FILE.FileName: test2.jpg
FILE.FileDateTime: 1015448798
FILE.FileDateTime: 1017666176
FILE.FileSize: 1240
FILE.SectionsFound: COMPUTED, ANY_TAG, IFD0, THUMBNAIL, COMMENT
COMPUTED.Copyright.Photographer: Photo (c) M.Boerger
COMPUTED.Copyright.Editor: Edited by M.Boerger.
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?>
COMMENT.2: Comment #3end
]]>
<!-- Version 4.3 will provide additional lines
THUMBNAIL.JPEGInterchangeFormat: 134
@ -231,26 +236,43 @@ THUMBNAIL.Thumbnail.Height: 1
</para>
<note>
<para>
When an Exif header contains a Copyright note this itself can contain
two values. As the solution is inconsitent in the Exif 2.10 standard the
COMPUTED section will return both entries <emphasis>Copyright.Photographer</emphasis>
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.
</para>
<para>
When an Exif header contains a Copyright note this itself can contain two
values. As the solution is inconsitent in the Exif 2.10 standard the COMPUTED
section will return both entries <emphasis>Copyright.Photographer</emphasis>
and <emphasis>Copyright.Editor</emphasis> 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.
first entry if the datatype was wrong (normal behaviour of Exif). The
COMPUTED will contain also an entry <emphasis>Copyright</emphasis> Which
is either the original copyright string or it is a comma separated list of
photo and editor copyright.
</para>
</note>
<note>
<para>
The 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.
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 <emphasis>UserCommentEncoding</emphasis> and
<emphasis>UserComment</emphasis>. The entry <emphasis>UserComment</emphasis>
is available in both cases so it should be used in preference to the value
in IFD0 section.
</para>
<para>
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. This was added in PHP 4.3.
</para>
</note>
<note>
<para>
Height and Width are computed the same way <function>getimagesize</function>
does so their values must not be part of any header returned. Also html is
a height/width text string to be used inside a normal <acronym>HTML</acronym>.
a height/width text string to be used inside normal <acronym>HTML</acronym>.
</para>
</note>
<note>
@ -259,7 +281,8 @@ THUMBNAIL.Thumbnail.Height: 1
data including arrays (returned as such). Also the size of an embedded thumbnail
is returned in <emphasis>THUMBNAIL</emphasis> subarray and the function
<function>exif_read_data</function> can return thumbnails in <acronym>TIFF</acronym>
format.
format. Last but not least there is no longer a maximum legth for returned
values (not until memory limit is reached).
</para>
</note>
<note>
@ -267,7 +290,11 @@ THUMBNAIL.Thumbnail.Height: 1
This function is only available in PHP 4 compiled using
<option role="configure">--enable-exif</option>.
Its functionality and behaviour has changed in PHP 4.2. Earlier versions
are very unstable.
are very unstable.
</simpara>
<simpara>
Since PHP 4.3 user comment can automatically change encoding if PHP 4 was
compiled using <option role="configure">--enable-mbstring</option>.
</simpara>
<simpara>
This function does not require the GD image library.