<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<head>
<meta http-equiv="content-type" content="text/html; charset=UTF-8">
<title>Enhances the contrast of a color image</title>
</head>
<body><div class="manualnavbar" style="text-align: center;">
<div class="prev" style="text-align: left; float: left;"><a href="imagick.contrastimage.html">Imagick::contrastImage</a></div>
<div class="next" style="text-align: right; float: right;"><a href="imagick.convolveimage.html">Imagick::convolveImage</a></div>
<div class="up"><a href="class.imagick.html">Imagick</a></div>
<div class="home"><a href="index.html">PHP Manual</a></div>
</div><hr /><div id="imagick.contraststretchimage" class="refentry">
<div class="refnamediv">
<h1 class="refname">Imagick::contrastStretchImage</h1>
<p class="verinfo">(PECL imagick 2.0.0)</p><p class="refpurpose"><span class="refname">Imagick::contrastStretchImage</span> — <span class="dc-title">Enhances the contrast of a color image</span></p>
</div>
<div class="refsect1 description" id="refsect1-imagick.contraststretchimage-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">bool</span> <span class="methodname"><strong>Imagick::contrastStretchImage</strong></span>
( <span class="methodparam"><span class="type">float</span> <code class="parameter">$black_point</code></span>
, <span class="methodparam"><span class="type">float</span> <code class="parameter">$white_point</code></span>
[, <span class="methodparam"><span class="type">int</span> <code class="parameter">$channel</code><span class="initializer"> = Imagick::CHANNEL_ALL</span></span>
] )</div>
<p class="para rdfs-comment">
Enhances the contrast of a color image by adjusting the pixels
color to span the entire range of colors available. This method is available if Imagick has been compiled against ImageMagick version 6.2.9 or newer.
</p>
</div>
<div class="refsect1 parameters" id="refsect1-imagick.contraststretchimage-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<span class="term"><em><code class="parameter">black_point</code></em></span>
<dd>
<p class="para">
The black point.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">white_point</code></em></span>
<dd>
<p class="para">
The white point.
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">channel</code></em></span>
<dd>
<p class="para">
Provide any channel constant that is valid for your channel mode. To
apply to more than one channel, combine channeltype constants using
bitwise operators. <strong><code>Imagick::CHANNEL_ALL</code></strong>. Refer to this
list of <a href="imagick.constants.html#imagick.constants.channel" class="link">channel constants</a>.
</p>
</dd>
</dt>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-imagick.contraststretchimage-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns <strong><code>TRUE</code></strong> on success.
</p>
</div>
</div><hr /><div class="manualnavbar" style="text-align: center;">
<div class="prev" style="text-align: left; float: left;"><a href="imagick.contrastimage.html">Imagick::contrastImage</a></div>
<div class="next" style="text-align: right; float: right;"><a href="imagick.convolveimage.html">Imagick::convolveImage</a></div>
<div class="up"><a href="class.imagick.html">Imagick</a></div>
<div class="home"><a href="index.html">PHP Manual</a></div>
</div></body></html>
