<!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>Apply a 3x3 convolution matrix, using coefficient and offset</title> </head> <body><div class="manualnavbar" style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.imagecolortransparent.html">imagecolortransparent</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.imagecopy.html">imagecopy</a></div> <div class="up"><a href="ref.image.html">GD and Image Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div> </div><hr /><div id="function.imageconvolution" class="refentry"> <div class="refnamediv"> <h1 class="refname">imageconvolution</h1> <p class="verinfo">(PHP 5 >= 5.1.0)</p><p class="refpurpose"><span class="refname">imageconvolution</span> — <span class="dc-title">Apply a 3x3 convolution matrix, using coefficient and offset</span></p> </div> <div class="refsect1 description" id="refsect1-function.imageconvolution-description"> <h3 class="title">Description</h3> <div class="methodsynopsis dc-description"> <span class="type">bool</span> <span class="methodname"><strong>imageconvolution</strong></span> ( <span class="methodparam"><span class="type">resource</span> <code class="parameter">$image</code></span> , <span class="methodparam"><span class="type">array</span> <code class="parameter">$matrix</code></span> , <span class="methodparam"><span class="type">float</span> <code class="parameter">$div</code></span> , <span class="methodparam"><span class="type">float</span> <code class="parameter">$offset</code></span> )</div> <p class="para rdfs-comment"> Applies a convolution matrix on the image, using the given coefficient and offset. </p> </div> <div class="refsect1 parameters" id="refsect1-function.imageconvolution-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">matrix</code></em></span> <dd> <p class="para"> A 3x3 matrix: an array of three arrays of three floats. </p> </dd> </dt> <dt> <span class="term"><em><code class="parameter">div</code></em></span> <dd> <p class="para"> The divisor of the result of the convolution, used for normalization. </p> </dd> </dt> <dt> <span class="term"><em><code class="parameter">offset</code></em></span> <dd> <p class="para"> Color offset. </p> </dd> </dt> </dl> </p> </div> <div class="refsect1 returnvalues" id="refsect1-function.imageconvolution-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.imageconvolution-examples"> <h3 class="title">Examples</h3> <p class="para"> <div class="example" id="example-3200"> <p><strong>Example #1 Embossing the PHP.net logo</strong></p> <div class="example-contents"> <div class="phpcode"><code><span style="color: #000000"> <span style="color: #0000BB"><?php<br />$image </span><span style="color: #007700">= </span><span style="color: #0000BB">imagecreatefromgif</span><span style="color: #007700">(</span><span style="color: #DD0000">'http://www.php.net/images/php.gif'</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">$emboss </span><span style="color: #007700">= array(array(</span><span style="color: #0000BB">2</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">), array(</span><span style="color: #0000BB">0</span><span style="color: #007700">, -</span><span style="color: #0000BB">1</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">), array(</span><span style="color: #0000BB">0</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">, -</span><span style="color: #0000BB">1</span><span style="color: #007700">));<br /></span><span style="color: #0000BB">imageconvolution</span><span style="color: #007700">(</span><span style="color: #0000BB">$image</span><span style="color: #007700">, </span><span style="color: #0000BB">$emboss</span><span style="color: #007700">, </span><span style="color: #0000BB">1</span><span style="color: #007700">, </span><span style="color: #0000BB">127</span><span style="color: #007700">);<br /><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 /></span><span style="color: #0000BB">imagepng</span><span style="color: #007700">(</span><span style="color: #0000BB">$image</span><span style="color: #007700">, </span><span style="color: #0000BB">null</span><span style="color: #007700">, </span><span style="color: #0000BB">9</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?></span> </span> </code></div> </div> <div class="example-contents"><p>The above example will output:</p></div> <div class="mediaobject"> <div class="imageobject"> <img src="images/21009b70229598c6a80eef8b45bf282b-imageconvolution_emboss.png" alt="Output of example : Embossing the PHP.net logo" width="120" height="67" /> </div> </div> </div> <div class="example" id="example-3201"> <p><strong>Example #2 Gaussian blur</strong></p> <div class="example-contents"> <div class="phpcode"><code><span style="color: #000000"> <span style="color: #0000BB"><?php<br />$image </span><span style="color: #007700">= </span><span style="color: #0000BB">imagecreatetruecolor</span><span style="color: #007700">(</span><span style="color: #0000BB">180</span><span style="color: #007700">,</span><span style="color: #0000BB">40</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">// Writes the text and apply a gaussian blur on the image<br /></span><span style="color: #0000BB">imagestring</span><span style="color: #007700">(</span><span style="color: #0000BB">$image</span><span style="color: #007700">, </span><span style="color: #0000BB">5</span><span style="color: #007700">, </span><span style="color: #0000BB">10</span><span style="color: #007700">, </span><span style="color: #0000BB">8</span><span style="color: #007700">, </span><span style="color: #DD0000">'Gaussian Blur Text'</span><span style="color: #007700">, </span><span style="color: #0000BB">0x00ff00</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$gaussian </span><span style="color: #007700">= array(array(</span><span style="color: #0000BB">1.0</span><span style="color: #007700">, </span><span style="color: #0000BB">2.0</span><span style="color: #007700">, </span><span style="color: #0000BB">1.0</span><span style="color: #007700">), array(</span><span style="color: #0000BB">2.0</span><span style="color: #007700">, </span><span style="color: #0000BB">4.0</span><span style="color: #007700">, </span><span style="color: #0000BB">2.0</span><span style="color: #007700">), array(</span><span style="color: #0000BB">1.0</span><span style="color: #007700">, </span><span style="color: #0000BB">2.0</span><span style="color: #007700">, </span><span style="color: #0000BB">1.0</span><span style="color: #007700">));<br /></span><span style="color: #0000BB">imageconvolution</span><span style="color: #007700">(</span><span style="color: #0000BB">$image</span><span style="color: #007700">, </span><span style="color: #0000BB">$gaussian</span><span style="color: #007700">, </span><span style="color: #0000BB">16</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">// Rewrites the text for comparison<br /></span><span style="color: #0000BB">imagestring</span><span style="color: #007700">(</span><span style="color: #0000BB">$image</span><span style="color: #007700">, </span><span style="color: #0000BB">5</span><span style="color: #007700">, </span><span style="color: #0000BB">10</span><span style="color: #007700">, </span><span style="color: #0000BB">18</span><span style="color: #007700">, </span><span style="color: #DD0000">'Gaussian Blur Text'</span><span style="color: #007700">, </span><span style="color: #0000BB">0x00ff00</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">header</span><span style="color: #007700">(</span><span style="color: #DD0000">'Content-Type: image/png'</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">imagepng</span><span style="color: #007700">(</span><span style="color: #0000BB">$image</span><span style="color: #007700">, </span><span style="color: #0000BB">null</span><span style="color: #007700">, </span><span style="color: #0000BB">9</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?></span> </span> </code></div> </div> <div class="example-contents"><p>The above example will output:</p></div> <div class="mediaobject"> <div class="imageobject"> <img src="images/21009b70229598c6a80eef8b45bf282b-imageconvolution_gaussian.png" alt="Output of example : Gaussian blur" width="180" height="40" /> </div> </div> </div> </p> </div> <div class="refsect1 notes" id="refsect1-function.imageconvolution-notes"> <h3 class="title">Notes</h3> <blockquote class="note"><p><strong class="note">Note</strong>: <span class="simpara">This function is only available if PHP is compiled with the bundled version of the GD library.</span></p></blockquote> </div> <div class="refsect1 seealso" id="refsect1-function.imageconvolution-seealso"> <h3 class="title">See Also</h3> <p class="para"> <ul class="simplelist"> <li class="member"> <span class="function"><a href="function.imagefilter.html" class="function" rel="rdfs-seeAlso">imagefilter()</a> - Applies a filter to an image</span></li> </ul> </p> </div> </div><hr /><div class="manualnavbar" style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.imagecolortransparent.html">imagecolortransparent</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.imagecopy.html">imagecopy</a></div> <div class="up"><a href="ref.image.html">GD and Image Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div> </div></body></html>