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<?xml version="1.0" encoding="iso-8859-1"?>
<!-- $Revision: 1.4 $ -->
<!-- splitted from ./en/functions/image.xml, last change in rev 1.36 -->
<refentry id="function.imagecolorat">
<refnamediv>
<refname>imagecolorat</refname>
<refpurpose>Get the index of the color of a pixel</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<methodsynopsis>
<type>int</type><methodname>imagecolorat</methodname>
<methodparam><type>resource</type><parameter>image</parameter></methodparam>
<methodparam><type>int</type><parameter>x</parameter></methodparam>
<methodparam><type>int</type><parameter>y</parameter></methodparam>
</methodsynopsis>
<para>
Returns the index of the color of the pixel at the
specified location in the image specified by <parameter>image</parameter>.
</para>
<para>
If PHP is compiled against GD library 2.0 or higher and the image is a
truecolor image, this function returns the RGB value of that pixel as
integer. Use bitshifting and masking to access the distinct red, green and blue
component values:
<example>
<title>Access distinct RGB values</title>
<programlisting role="php">
<![CDATA[
<?php
$im = ImageCreateFromPng("rockym.png");
$rgb = ImageColorAt($im, 100, 100);
$r = ($rgb >> 16) & 0xFF;
$g = ($rgb >> 8) & 0xFF;
$b = $rgb & 0xFF;
?>
]]>
</programlisting>
</example>
</para>
<para>
See also <function>imagecolorset</function> and
<function>imagecolorsforindex</function>.
</para>
</refsect1>
</refentry>
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