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<title>Adjusts the levels of an image</title>
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<h1 class="refname">Imagick::levelImage</h1>
<p class="verinfo">(PECL imagick 2.0.0)</p><p class="refpurpose"><span class="refname">Imagick::levelImage</span> — <span class="dc-title">Adjusts the levels of an image</span></p>
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<div class="refsect1 description" id="refsect1-imagick.levelimage-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">bool</span> <span class="methodname"><strong>Imagick::levelImage</strong></span>
( <span class="methodparam"><span class="type">float</span> <code class="parameter">$blackPoint</code></span>
, <span class="methodparam"><span class="type">float</span> <code class="parameter">$gamma</code></span>
, <span class="methodparam"><span class="type">float</span> <code class="parameter">$whitePoint</code></span>
[, <span class="methodparam"><span class="type">int</span> <code class="parameter">$channel</code><span class="initializer"> = Imagick::CHANNEL_ALL</span></span>
] )</div>
<p class="para rdfs-comment">
Adjusts the levels of an image by scaling the colors falling
between specified white and black points to the full
available quantum range. The parameters provided represent
the black, mid, and white points. The black point specifies
the darkest color in the image. Colors darker than the black
point are set to zero. Mid point specifies a gamma
correction to apply to the image. White point specifies the
lightest color in the image. Colors brighter than the white
point are set to the maximum quantum value.
</p>
</div>
<div class="refsect1 parameters" id="refsect1-imagick.levelimage-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<span class="term"><em><code class="parameter">blackPoint</code></em></span>
<dd>
<p class="para">
The image black point
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">gamma</code></em></span>
<dd>
<p class="para">
The gamma value
</p>
</dd>
</dt>
<dt>
<span class="term"><em><code class="parameter">whitePoint</code></em></span>
<dd>
<p class="para">
The image 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. 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.levelimage-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns <strong><code>TRUE</code></strong> on success.
</p>
</div>
<div class="refsect1 errors" id="refsect1-imagick.levelimage-errors">
<h3 class="title">Errors/Exceptions</h3>
<p class="para">
Throws ImagickException on error.
</p>
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