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
|
<?xml version="1.0" encoding="iso-8859-1"?>
<!-- $Revision: 1.10 $ -->
<refentry xml:id="function.imagecolorclosestalpha" xmlns="http://docbook.org/ns/docbook">
<refnamediv>
<refname>imagecolorclosestalpha</refname>
<refpurpose>Get the index of the closest color to the specified color + alpha</refpurpose>
</refnamediv>
<refsect1 role="description">
&reftitle.description;
<methodsynopsis>
<type>int</type><methodname>imagecolorclosestalpha</methodname>
<methodparam><type>resource</type><parameter>image</parameter></methodparam>
<methodparam><type>int</type><parameter>red</parameter></methodparam>
<methodparam><type>int</type><parameter>green</parameter></methodparam>
<methodparam><type>int</type><parameter>blue</parameter></methodparam>
<methodparam><type>int</type><parameter>alpha</parameter></methodparam>
</methodsynopsis>
<para>
Returns the index of the color in the palette of the image which
is "closest" to the specified <acronym>RGB</acronym> value and
<parameter>alpha</parameter> level.
</para>
</refsect1>
<refsect1 role="parameters">
&reftitle.parameters;
<para>
<variablelist>
&gd.image.description;
<varlistentry>
<term><parameter>red</parameter></term>
<listitem>
<para>
Value of red component.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>green</parameter></term>
<listitem>
<para>
Value of green component.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>blue</parameter></term>
<listitem>
<para>
Value of blue component.
</para>
</listitem>
</varlistentry>
<varlistentry>
<term><parameter>alpha</parameter></term>
<listitem>
<para>
A value between <literal>0</literal> and <literal>127</literal>.
<literal>0</literal> indicates completely opaque while
<literal>127</literal> indicates completely transparent.
</para>
</listitem>
</varlistentry>
</variablelist>
The colors parameters are integers between 0 and 255 or hexadecimals
between 0x00 and 0xFF.
</para>
</refsect1>
<refsect1 role="returnvalues">
&reftitle.returnvalues;
<para>
Returns the index of the closest color in the palette.
</para>
</refsect1>
<refsect1 role="examples">
&reftitle.examples;
<para>
<example>
<title>Search for a set of colors in an image</title>
<programlisting role="php">
<![CDATA[
<?php
// Start with an image and convert it to a palette-based image
$im = imagecreatefrompng('figures/imagecolorclosest.png');
imagetruecolortopalette($im, false, 255);
// Search colors (RGB)
$colors = array(
array(254, 145, 154, 50),
array(153, 145, 188, 127),
array(153, 90, 145, 0),
array(255, 137, 92, 84)
);
// Loop through each search and find the closest color in the palette.
// Return the search number, the search RGB and the converted RGB match
foreach($colors as $id => $rgb)
{
$result = imagecolorclosestalpha($im, $rgb[0], $rgb[1], $rgb[2], $rgb[3]);
$result = imagecolorsforindex($im, $result);
$result = "({$result['red']}, {$result['green']}, {$result['blue']}, {$result['alpha']})";
echo "#$id: Search ($rgb[0], $rgb[1], $rgb[2], $rgb[3]); Closest match: $result.\n";
}
imagedestroy($im);
?>
]]>
</programlisting>
&example.outputs.similar;
<screen>
<![CDATA[
#0: Search (254, 145, 154, 50); Closest match: (252, 150, 148, 0).
#1: Search (153, 145, 188, 127); Closest match: (148, 150, 196, 0).
#2: Search (153, 90, 145, 0); Closest match: (148, 90, 156, 0).
#3: Search (255, 137, 92, 84); Closest match: (252, 150, 92, 0).
]]>
</screen>
</example>
</para>
</refsect1>
<refsect1 role="notes">
&reftitle.notes;
¬e.gd.2;
</refsect1>
<refsect1 role="seealso">
&reftitle.seealso;
<para>
<simplelist>
<member><function>imagecolorexactalpha</function></member>
<member><function>imagecolorclosest</function></member>
<member><function>imagecolorclosesthwb</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:"../../../../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
-->
|
