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<?xml version="1.0" encoding="iso-8859-1"?>
<!-- $Revision: 1.6 $ -->
<!-- splitted from ./en/functions/image.xml, last change in rev 1.36 -->
<refentry id="function.imagecopyresampled">
<refnamediv>
<refname>imagecopyresampled</refname>
<refpurpose>Copy and resize part of an image with resampling</refpurpose>
</refnamediv>
<refsect1>
<title>Description</title>
<methodsynopsis>
<type>bool</type><methodname>imagecopyresampled</methodname>
<methodparam><type>resource</type><parameter>dst_image</parameter></methodparam>
<methodparam><type>resource</type><parameter>src_image</parameter></methodparam>
<methodparam><type>int</type><parameter>dst_x</parameter></methodparam>
<methodparam><type>int</type><parameter>dst_y</parameter></methodparam>
<methodparam><type>int</type><parameter>src_x</parameter></methodparam>
<methodparam><type>int</type><parameter>src_y</parameter></methodparam>
<methodparam><type>int</type><parameter>dst_w</parameter></methodparam>
<methodparam><type>int</type><parameter>dst_h</parameter></methodparam>
<methodparam><type>int</type><parameter>src_w</parameter></methodparam>
<methodparam><type>int</type><parameter>src_h</parameter></methodparam>
</methodsynopsis>
<para>
<function>imagecopyresampled</function> copies a rectangular
portion of one image to another image, smoothly interpolating pixel
values so that, in particular, reducing the size of an image still
retains a great deal of clarity.
&return.success;
</para>
<para>
<parameter>dst_image</parameter> is the destination image,
<parameter>src_image</parameter> is the source image identifier. If
the source and destination coordinates and width and heights
differ, appropriate stretching or shrinking of the image fragment
will be performed. The coordinates refer to the upper left
corner. This function can be used to copy regions within the
same image (if <parameter>dst_image</parameter> is the same as
<parameter>src_image</parameter>) but if the regions overlap the
results will be unpredictable.
</para>
<note>
<para>
There is a problem due to palette image limitations (255+1 colors).
Resampling or filtering an image commonly needs more colors than 255, a
kind of approximation is used to calculate the new resampled pixel and its
color. With a palette image we try to allocate a new color, if that
failed, we choose the closest (in theory) computed color. This is
not always the closest visual color. That may produce a weird result, like
blank (or visually blank) images. To skip this problem, please use a
truecolor image as a destination image, such as one created by
<function>imagecreatetruecolor</function>.
</para>
</note>
¬e.gd.2;
</refsect1>
<refsect1>
&reftitle.examples;
<para>
<example>
<title>Simple example</title>
<para>
This example will resample an image to half its original size.
</para>
<programlisting role="php">
<![CDATA[
<?php
// The file
$filename = 'test.jpg';
$percent = 0.5;
// Content type
header('Content-type: image/jpeg');
// Get new dimensions
list($width, $height) = getimagesize($filename);
$new_width = $width * $percent;
$new_height = $height * $percent;
// Resample
$image_p = imagecreatetruecolor($new_width, $new_height);
$image = imagecreatefromjpeg($filename);
imagecopyresampled($image_p, $image, 0, 0, 0, 0, $new_width, $new_height, $width, $height);
// Output
imagejpeg($image_p, null, 100);
?>
]]>
</programlisting>
</example>
</para>
<para>
<example>
<title>Resampling an image proportionally</title>
<para>
This example will display an image with the maximum width,
or height, of 200 pixels.
</para>
<programlisting role="php">
<![CDATA[
<?php
// The file
$filename = 'test.jpg';
// Set a maximum height and width
$width = 200;
$height = 200;
// Content type
header('Content-type: image/jpeg');
// Get new dimensions
list($width_orig, $height_orig) = getimagesize($filename);
if ($width && ($width_orig < $height_orig)) {
$width = ($height / $height_orig) * $width_orig;
} else {
$height = ($width / $width_orig) * $height_orig;
}
// Resample
$image_p = imagecreatetruecolor($width, $height);
$image = imagecreatefromjpeg($filename);
imagecopyresampled($image_p, $image, 0, 0, 0, 0, $width, $height, $width_orig, $height_orig);
// Output
imagejpeg($image_p, null, 100);
?>
]]>
</programlisting>
</example>
</para>
</refsect1>
<refsect1>
&reftitle.seealso;
<para>
<function>imagecopyresized</function>
</para>
</refsect1>
</refentry>
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