helly Tue Mar 12 08:48:33 2002 EDT
Modified files:
/phpdoc/en/functions image.xml
Log:
-exif functions
Index: phpdoc/en/functions/image.xml
diff -u phpdoc/en/functions/image.xml:1.80 phpdoc/en/functions/image.xml:1.81
--- phpdoc/en/functions/image.xml:1.80 Fri Mar 8 14:43:29 2002
+++ phpdoc/en/functions/image.xml Tue Mar 12 08:48:33 2002
@@ -1,5 +1,5 @@
<?xml version="1.0" encoding="iso-8859-1"?>
-<!-- $Revision: 1.80 $ -->
+<!-- $Revision: 1.81 $ -->
<reference id="ref.image">
<title>Image functions</title>
<titleabbrev>Image</titleabbrev>
@@ -8,13 +8,19 @@
<simpara>
You can use the image functions in PHP to get the size of
<acronym>JPEG</acronym>, <acronym>GIF</acronym>,
- <acronym>PNG</acronym>, <acronym>TIFF</acronym> and
- <acronym>SWF</acronym> images, and if
+ <acronym>PNG</acronym>, <acronym>SWF</acronym>,
+ <acronym>TIFF</acronym> and <acronym>JPEG2000</acronym> images, and if
you have the <acronym>GD</acronym> library (available at <ulink
url="&url.gd;">&url.gd;</ulink>) you will also be able to create
and manipulate images.
</simpara>
<simpara>
+ If you have PHP compiled with <option role="configure">--enable-exif</option>
+ you are able to work with information stored in headers of
+ <acronym>JPEG</acronym> and <acronym>TIFF</acronym> images. These
+ functions do not require <acronym>GD</acronym> library.
+ </simpara>
+ <simpara>
The format of images you are able to manipulate depend on the
version of gd you install, and any other libraries gd might need
to access those image formats. Versions of gd older than gd-1.6
@@ -35,6 +41,52 @@
</simpara>
</partintro>
+ <refentry id="function.exif-imagetype">
+ <refnamediv>
+ <refname>exif_imagetype</refname>
+ <refpurpose>Determine the type of an image.</refpurpose>
+ </refnamediv>
+ <refsect1>
+ <title>Description</title>
+ <methodsynopsis>
+ <type>int|false</type><methodname>exif_thumbnail</methodname>
+ <methodparam><type>string</type><parameter>filename</parameter></methodparam>
+ </methodsynopsis>
+ <para>
+ <function>exif_imagetype</function> reads the first bytes of an image and
+ checks its signature. When a correct signature is found a constant will be
+ returned otherwise the return value is &false; The return value is the same
+ value that <function>GetImageSize</function> returns in index 2 but this
+ function is much faster.
+ </para>
+ <para>
+ The following constants are defined:
+ 1 = IMAGETYPE_GIF, 2 = IMAGETYPE_JPG, 3 = IMAGETYPE_PNG, 4 = IMAGETYPE_SWF,
+ 5 = IMAGETYPE_PSD, 6 = IMAGETYPE_BMP, 7 = IMAGETYPE_TIFF_II (intel byte order),
+ 8 = IMAGETYPE_TIFF_MM (motorola byte order), 9 = IMAGETYPE_JPC, 10 =
+IMAGETYPE_JP2,
+ 11 = IMAGETYPE_JPX.
+ </para>
+ <para>
+ This function can be used to avoid calls to other exif functions with unsupported
+ file teypes or in conjunction with $_SERVER['HTTP_ACCEPT'] to check whether or
+ not the viewer is able to see a specific image in his browser.
+ </para>
+ <para>
+ <note>
+ <simpara>
+ This function is only available in PHP 4 compiled using --enable-exif.
+ </simpara>
+ <simpara>
+ This function does not require the GD image library.
+ </simpara>
+ <simpara>
+ See also <function>GetImageSize</function>.
+ </simpara>
+ </note>
+ </para>
+ </refsect1>
+ </refentry>
+
<refentry id="function.exif-read-data">
<refnamediv>
<refname>exif_read_data</refname>
@@ -125,7 +177,7 @@
</note>
<para>
<example>
- <title><function>read_exif_data</function> example</title>
+ <title><function>exif_read_data</function> example</title>
<programlisting role="php">
<![CDATA[
<?php
@@ -167,6 +219,11 @@
COMMENT.1: Comment #2.
COMMENT.2: Comment #3end?>
]]>
+<!-- Version 4.3 will provide additional lines
+THUMBNAIL.JPEGInterchangeFormat: 134
+THUMBNAIL.Thumbnail.Height: 1
+THUMBNAIL.Thumbnail.Height: 1
+-->
</screen>
</para>
</example>
@@ -196,6 +253,15 @@
</para>
</note>
<note>
+ <para>
+ Starting from PHP 4.3 the function can read all embedded <acronym>IFD</acronym>
+ 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.
+ </para>
+ </note>
+ <note>
<simpara>
This function is only available in PHP 4 compiled using --enable-exif.
Its functionality and behaviour has changed in PHP 4.2. Earlier versions
@@ -221,6 +287,8 @@
<methodsynopsis>
<type>string</type><methodname>exif_thumbnail</methodname>
<methodparam><type>string</type><parameter>filename</parameter></methodparam>
+ <methodparam
+choice="opt"><type>int</type><parameter>&width</parameter></methodparam>
+ <methodparam
+choice="opt"><type>int</type><parameter>&height</parameter></methodparam>
</methodsynopsis>
<para>
<function>exif_thumbnail</function> reads the embedded thumbnail of
@@ -228,6 +296,17 @@
will be returned.
</para>
<para>
+ Both parameters <parameter>width</parameter> and <parameter>height</parameter> are
+ available since PHP 4.3 and return the size of the thumbnail. It is possible that
+ <function>exif_thumbnail</function> cannot create and image but determine the its
+ size. In this case the return value is false but <parameter>width</parameter> and
+ <parameter>height</parameter> are set.
+ </para>
+ <para>
+ Starting from version PHP 4.3 the function <function>exif_thumbnail</function> can
+ return thumbnails in <acronym>TIFF</acronym> format.
+ </para>
+ <para>
<note>
<simpara>
This function is only available in PHP 4 compiled using --enable-exif.
@@ -270,8 +349,10 @@
Returns an array with 4 elements. Index 0 contains the width of
the image in pixels. Index 1 contains the height. Index 2 a
flag indicating the type of the image. 1 = GIF, 2 = JPG, 3 =
- PNG, 4 = SWF, 5 = PSD, 6 = BMP. Index 3 is a text string with the correct
- "height=xxx width=xxx" string that can be used directly in an IMG
+ PNG, 4 = SWF, 5 = PSD, 6 = BMP, 7 = TIFF(intel byte order),
+ 8 = TIFF(motorola byte order, 9 = JPC, 10 = JP2, 11 = JPX.
+ Index 3 is a text string with the correct
+ height="yyy" width="xxx" string that can be used directly in an IMG
tag.
<example>
<title>GetImageSize (file)</title>
@@ -331,10 +412,16 @@
</example>
<note>
<simpara>
+ TIFF support was added in PHP 4.2. JPEG2000 support will be added
+ in PHP 4.3.
+ </simpara>
+ <simpara>
This function does not require the GD image library.
</simpara>
- </note>
- <note>
+ <simpara>
+ See also <function>exif_imagetype</function>,
+<function>exif_read_data</function>
+ and <function>exif_thumbnail</function>.
+ </simpara>
<simpara>
URL support was added in PHP 4.0.5
</simpara>
