<!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 gamma correction to a GD image</title> </head> <body><div class="manualnavbar" style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.imagefttext.html">imagefttext</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.imagegd2.html">imagegd2</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.imagegammacorrect" class="refentry"> <div class="refnamediv"> <h1 class="refname">imagegammacorrect</h1> <p class="verinfo">(PHP 4, PHP 5)</p><p class="refpurpose"><span class="refname">imagegammacorrect</span> — <span class="dc-title">Apply a gamma correction to a GD image</span></p> </div> <div class="refsect1 description" id="refsect1-function.imagegammacorrect-description"> <h3 class="title">Description</h3> <div class="methodsynopsis dc-description"> <span class="type">bool</span> <span class="methodname"><strong>imagegammacorrect</strong></span> ( <span class="methodparam"><span class="type">resource</span> <code class="parameter">$image</code></span> , <span class="methodparam"><span class="type">float</span> <code class="parameter">$inputgamma</code></span> , <span class="methodparam"><span class="type">float</span> <code class="parameter">$outputgamma</code></span> )</div> <p class="para rdfs-comment"> Applies gamma correction to the given gd <em><code class="parameter">image</code></em> given an input and an output gamma. </p> </div> <div class="refsect1 parameters" id="refsect1-function.imagegammacorrect-parameters"> <h3 class="title">Parameters</h3> <p class="para"> <dl> <dt> <span class="term"><em><code class="parameter"> image</code></em></span><dd> <p class="para">An image resource, returned by one of the image creation functions, such as <span class="function"><a href="function.imagecreatetruecolor.html" class="function">imagecreatetruecolor()</a></span>.</p></dd> </dt> <dt> <span class="term"><em><code class="parameter">inputgamma</code></em></span> <dd> <p class="para"> The input gamma. </p> </dd> </dt> <dt> <span class="term"><em><code class="parameter">outputgamma</code></em></span> <dd> <p class="para"> The output gamma. </p> </dd> </dt> </dl> </p> </div> <div class="refsect1 returnvalues" id="refsect1-function.imagegammacorrect-returnvalues"> <h3 class="title">Return Values</h3> <p class="para"> Returns <strong><code>TRUE</code></strong> on success or <strong><code>FALSE</code></strong> on failure. </p> </div> <div class="refsect1 examples" id="refsect1-function.imagegammacorrect-examples"> <h3 class="title">Examples</h3> <p class="para"> <div class="example" id="example-3244"> <p><strong>Example #1 <span class="function"><strong>imagegammacorrect()</strong></span> usage</strong></p> <div class="example-contents"> <div class="phpcode"><code><span style="color: #000000"> <span style="color: #0000BB"><?php<br /></span><span style="color: #FF8000">// Create image instance<br /></span><span style="color: #0000BB">$im </span><span style="color: #007700">= </span><span style="color: #0000BB">imagecreatefromgif</span><span style="color: #007700">(</span><span style="color: #DD0000">'php.gif'</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">// Correct gamma, out = 1.537<br /></span><span style="color: #0000BB">imagegammacorrect</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">, </span><span style="color: #0000BB">1.0</span><span style="color: #007700">, </span><span style="color: #0000BB">1.537</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">// Save and free image<br /></span><span style="color: #0000BB">imagegif</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">, </span><span style="color: #DD0000">'./php_gamma_corrected.gif'</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> </p> </div> </div><hr /><div class="manualnavbar" style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.imagefttext.html">imagefttext</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.imagegd2.html">imagegd2</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>