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<title>Scale an image using the given new width and height</title>
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<div class="refnamediv">
<h1 class="refname">imagescale</h1>
<p class="verinfo">(PHP 5 >= 5.5.0, PHP 7)</p><p class="refpurpose"><span class="refname">imagescale</span> — <span class="dc-title">Scale an image using the given new width and height</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.imagescale-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">resource</span> <span class="methodname"><strong>imagescale</strong></span>
( <span class="methodparam"><span class="type">resource</span> <code class="parameter">$image</code></span>
, <span class="methodparam"><span class="type">int</span> <code class="parameter">$new_width</code></span>
[, <span class="methodparam"><span class="type">int</span> <code class="parameter">$new_height</code><span class="initializer"> = -1</span></span>
[, <span class="methodparam"><span class="type">int</span> <code class="parameter">$mode</code><span class="initializer"> = IMG_BILINEAR_FIXED</span></span>
]] )</div>
<p class="para rdfs-comment">
<span class="function"><strong>imagescale()</strong></span> scales an image using the given
interpolation algorithm.
</p>
</div>
<div class="refsect1 parameters" id="refsect1-function.imagescale-parameters">
<h3 class="title">Parameters</h3>
<dl>
<dt>
<code class="parameter">
image</code></dt>
<dd>
<p class="para">An image resource, returned by one of the image creation functions,
such as <span class="function"><a href="function.imagecreatetruecolor.html" class="function">imagecreatetruecolor()</a></span>.</p></dd>
<dt>
<code class="parameter">new_width</code></dt>
<dd>
<p class="para">
The width to scale the image to.
</p>
</dd>
<dt>
<code class="parameter">new_height</code></dt>
<dd>
<p class="para">
The height to scale the image to. If omitted or negative, the aspect
ratio will be preserved.
</p>
<div class="caution"><strong class="caution">Caution</strong>
<p class="para">
You should always provide the height if using PHP 5.5.18 or earlier, or
PHP 5.6.2 or earlier, as the aspect ratio calculation was incorrect.
</p>
</div>
</dd>
<dt>
<code class="parameter">mode</code></dt>
<dd>
<p class="para">
One of <strong><code>IMG_NEAREST_NEIGHBOUR</code></strong>,
<strong><code>IMG_BILINEAR_FIXED</code></strong>,
<strong><code>IMG_BICUBIC</code></strong>,
<strong><code>IMG_BICUBIC_FIXED</code></strong> or anything else (will use two
pass).
<blockquote class="note"><p><strong class="note">Note</strong>:
<span class="simpara">
<strong><code>IMG_WEIGHTED4</code></strong> is not yet supported.
</span>
</p></blockquote>
</p>
</dd>
</dl>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.imagescale-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Return the scaled image resource on success or <strong><code>FALSE</code></strong> on failure.
</p>
</div>
<div class="refsect1 changelog" id="refsect1-function.imagescale-changelog">
<h3 class="title">Changelog</h3>
<p class="para">
<table class="doctable informaltable">
<thead>
<tr>
<th>Version</th>
<th>Description</th>
</tr>
</thead>
<tbody class="tbody">
<tr>
<td>5.5.19/5.6.3</td>
<td>
The calculation of the height if <code class="parameter">new_height</code> was
negative or omitted was fixed; prior to these versions, the aspect
ratio was not maintained correctly.
</td>
</tr>
</tbody>
</table>
</p>
</div>
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