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<title>Set the blending mode for an image</title>
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<h1 class="refname">imagealphablending</h1>
<p class="verinfo">(PHP 4 >= 4.0.6, PHP 5)</p><p class="refpurpose"><span class="refname">imagealphablending</span> — <span class="dc-title">Set the blending mode for an image</span></p>
</div>
<div class="refsect1 description" id="refsect1-function.imagealphablending-description">
<h3 class="title">Description</h3>
<div class="methodsynopsis dc-description">
<span class="type">bool</span> <span class="methodname"><strong>imagealphablending</strong></span>
( <span class="methodparam"><span class="type">resource</span> <code class="parameter">$image</code></span>
, <span class="methodparam"><span class="type">bool</span> <code class="parameter">$blendmode</code></span>
)</div>
<p class="para rdfs-comment">
<span class="function"><strong>imagealphablending()</strong></span> allows for two different
modes of drawing on truecolor images. In blending mode, the
alpha channel component of the color supplied to all drawing function,
such as <span class="function"><a href="function.imagesetpixel.html" class="function">imagesetpixel()</a></span> determines how much of the
underlying color should be allowed to shine through. As a result, gd
automatically blends the existing color at that point with the drawing color,
and stores the result in the image. The resulting pixel is opaque. In
non-blending mode, the drawing color is copied literally with its alpha channel
information, replacing the destination pixel. Blending mode is not available
when drawing on palette images.
</p>
</div>
<div class="refsect1 parameters" id="refsect1-function.imagealphablending-parameters">
<h3 class="title">Parameters</h3>
<p class="para">
<dl>
<dt>
<span class="term"><em><code class="parameter">
image</code></em></span><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>
<dt>
<span class="term"><em><code class="parameter">blendmode</code></em></span>
<dd>
<p class="para">
Whether to enable the blending mode or not. On true color images
the default value is <strong><code>TRUE</code></strong> otherwise the default value is <strong><code>FALSE</code></strong>
</p>
</dd>
</dt>
</dl>
</p>
</div>
<div class="refsect1 returnvalues" id="refsect1-function.imagealphablending-returnvalues">
<h3 class="title">Return Values</h3>
<p class="para">
Returns <strong><code>TRUE</code></strong> on success or <strong><code>FALSE</code></strong> on failure.
</p>
</div>
<div class="refsect1 examples" id="refsect1-function.imagealphablending-examples">
<h3 class="title">Examples</h3>
<div class="example" id="example-3178">
<p><strong>Example #1 <span class="function"><strong>imagealphablending()</strong></span> usage example</strong></p>
<div class="example-contents">
<div class="phpcode"><code><span style="color: #000000">
<span style="color: #0000BB"><?php<br /></span><span style="color: #FF8000">// Create image<br /></span><span style="color: #0000BB">$im </span><span style="color: #007700">= </span><span style="color: #0000BB">imagecreatetruecolor</span><span style="color: #007700">(</span><span style="color: #0000BB">100</span><span style="color: #007700">, </span><span style="color: #0000BB">100</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">// Set alphablending to on<br /></span><span style="color: #0000BB">imagealphablending</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">, </span><span style="color: #0000BB">true</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">// Draw a square<br /></span><span style="color: #0000BB">imagefilledrectangle</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">, </span><span style="color: #0000BB">30</span><span style="color: #007700">, </span><span style="color: #0000BB">30</span><span style="color: #007700">, </span><span style="color: #0000BB">70</span><span style="color: #007700">, </span><span style="color: #0000BB">70</span><span style="color: #007700">, </span><span style="color: #0000BB">imagecolorallocate</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">, </span><span style="color: #0000BB">255</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">));<br /><br /></span><span style="color: #FF8000">// Output<br /></span><span style="color: #0000BB">header</span><span style="color: #007700">(</span><span style="color: #DD0000">'Content-type: image/png'</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">imagepng</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">imagedestroy</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?></span>
</span>
</code></div>
</div>
</div>
</div>
<div class="refsect1 notes" id="refsect1-function.imagealphablending-notes">
<h3 class="title">Notes</h3>
<blockquote class="note"><p><strong class="note">Note</strong>: <span class="simpara">This function requires GD 2.0.1 or later (2.0.28 or later is recommended).</span></p></blockquote>
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