/
exif-imagetype.xml
232 lines (229 loc) · 6.29 KB
/
exif-imagetype.xml
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
<?xml version="1.0" encoding="utf-8"?>
<!-- $Revision$ -->
<!-- splitted from ./en/functions/image.xml, last change in rev 1.81 -->
<refentry xml:id="function.exif-imagetype" xmlns="http://docbook.org/ns/docbook">
<refnamediv>
<refname>exif_imagetype</refname>
<refpurpose>Determine the type of an image</refpurpose>
</refnamediv>
<refsect1 role="description">
&reftitle.description;
<methodsynopsis>
<type class="union"><type>int</type><type>false</type></type><methodname>exif_imagetype</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.
</para>
<para>
<function>exif_imagetype</function> can be used to avoid calls to other
<link linkend="ref.exif">exif</link> functions with unsupported file types
or in conjunction with <varname>$_SERVER['HTTP_ACCEPT']</varname> to check
whether or not the viewer is able to see a specific image in the browser.
</para>
</refsect1>
<refsect1 role="parameters">
&reftitle.parameters;
<para>
<variablelist>
<varlistentry>
<term><parameter>filename</parameter></term>
<listitem>
<simpara>
The image being checked.
</simpara>
</listitem>
</varlistentry>
</variablelist>
</para>
</refsect1>
<refsect1 role="returnvalues">
&reftitle.returnvalues;
<para>
When a correct signature is found, the appropriate constant value 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
<function>exif_imagetype</function> is much faster.
</para>
<para>
The following constants are defined, and represent possible
<function>exif_imagetype</function> return values:
<table>
<title>Imagetype Constants</title>
<tgroup cols="2">
<thead>
<row>
<entry>Value</entry>
<entry>Constant</entry>
</row>
</thead>
<tbody>
<row>
<entry>1</entry>
<entry><constant>IMAGETYPE_GIF</constant></entry>
</row>
<row>
<entry>2</entry>
<entry><constant>IMAGETYPE_JPEG</constant></entry>
</row>
<row>
<entry>3</entry>
<entry><constant>IMAGETYPE_PNG</constant></entry>
</row>
<row>
<entry>4</entry>
<entry><constant>IMAGETYPE_SWF</constant></entry>
</row>
<row>
<entry>5</entry>
<entry><constant>IMAGETYPE_PSD</constant></entry>
</row>
<row>
<entry>6</entry>
<entry><constant>IMAGETYPE_BMP</constant></entry>
</row>
<row>
<entry>7</entry>
<entry><constant>IMAGETYPE_TIFF_II</constant> (intel byte order)</entry>
</row>
<row>
<entry>8</entry>
<entry>
<constant>IMAGETYPE_TIFF_MM</constant> (motorola byte order)
</entry>
</row>
<row>
<entry>9</entry>
<entry><constant>IMAGETYPE_JPC</constant></entry>
</row>
<row>
<entry>10</entry>
<entry><constant>IMAGETYPE_JP2</constant></entry>
</row>
<row>
<entry>11</entry>
<entry><constant>IMAGETYPE_JPX</constant></entry>
</row>
<row>
<entry>12</entry>
<entry><constant>IMAGETYPE_JB2</constant></entry>
</row>
<row>
<entry>13</entry>
<entry><constant>IMAGETYPE_SWC</constant></entry>
</row>
<row>
<entry>14</entry>
<entry><constant>IMAGETYPE_IFF</constant></entry>
</row>
<row>
<entry>15</entry>
<entry><constant>IMAGETYPE_WBMP</constant></entry>
</row>
<row>
<entry>16</entry>
<entry><constant>IMAGETYPE_XBM</constant></entry>
</row>
<row>
<entry>17</entry>
<entry><constant>IMAGETYPE_ICO</constant></entry>
</row>
<row>
<entry>18</entry>
<entry><constant>IMAGETYPE_WEBP</constant></entry>
</row>
<row>
<entry>19</entry>
<entry><constant>IMAGETYPE_AVIF</constant></entry>
</row>
</tbody>
</tgroup>
</table>
</para>
<note>
<para>
<function>exif_imagetype</function> will emit an <constant>E_NOTICE</constant>
and return &false; if it is unable to read enough bytes from the file to
determine the image type.
<!-- If the function finds an incomplete PNG header then it may emit an
<constant>E_WARNING</constant> instead. - Is this worth including? -->
</para>
</note>
</refsect1>
<refsect1 role="changelog">
&reftitle.changelog;
<para>
<informaltable>
<tgroup cols="2">
<thead>
<row>
<entry>&Version;</entry>
<entry>&Description;</entry>
</row>
</thead>
<tbody>
<row>
<entry>7.1.0</entry>
<entry>
Added WebP support.
</entry>
</row>
<row>
<entry>8.1.0</entry>
<entry>
Added AVIF support.
</entry>
</row>
</tbody>
</tgroup>
</informaltable>
</para>
</refsect1>
<refsect1 role="examples">
&reftitle.examples;
<para>
<example>
<title><function>exif_imagetype</function> example</title>
<programlisting role="php">
<![CDATA[
<?php
if (exif_imagetype('image.gif') != IMAGETYPE_GIF) {
echo 'The picture is not a gif';
}
?>
]]>
</programlisting>
</example>
</para>
</refsect1>
<refsect1 role="seealso">
&reftitle.seealso;
<para>
<simplelist>
<member><function>image_type_to_mime_type</function></member>
<member><function>getimagesize</function></member>
</simplelist>
</para>
</refsect1>
</refentry>
<!-- Keep this comment at the end of the file
Local variables:
mode: sgml
sgml-omittag:t
sgml-shorttag:t
sgml-minimize-attributes:nil
sgml-always-quote-attributes:t
sgml-indent-step:1
sgml-indent-data:t
indent-tabs-mode:nil
sgml-parent-document:nil
sgml-default-dtd-file:"~/.phpdoc/manual.ced"
sgml-exposed-tags:nil
sgml-local-catalogs:nil
sgml-local-ecat-files:nil
End:
vim600: syn=xml fen fdm=syntax fdl=2 si
vim: et tw=78 syn=sgml
vi: ts=1 sw=1
-->