function.imagecolorexactalpha.html
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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"><html> <head> <title>Get the index of the specified color + alpha</title> <meta http-equiv="content-type" content="text/html; charset=UTF-8"> </head> <body><div style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.imagecolorexact.html">imagecolorexact</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.imagecolormatch.html">imagecolormatch</a></div> <div class="up"><a href="ref.image.html">GD Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div></div><hr /><div id="function.imagecolorexactalpha" class="refentry"> <div class="refnamediv"> <h1 class="refname">imagecolorexactalpha</h1> <p class="verinfo">(PHP 4 >= 4.0.6, PHP 5)</p><p class="refpurpose"><span class="refname">imagecolorexactalpha</span> — <span class="dc-title">Get the index of the specified color + alpha</span></p> </div> <div class="refsect1 description"> <h3 class="title">Description</h3> <div class="methodsynopsis dc-description"> <span class="type">int</span> <span class="methodname"><b><b>imagecolorexactalpha</b></b></span> ( <span class="methodparam"><span class="type">resource</span> <tt class="parameter">$image</tt></span> , <span class="methodparam"><span class="type">int</span> <tt class="parameter">$red</tt></span> , <span class="methodparam"><span class="type">int</span> <tt class="parameter">$green</tt></span> , <span class="methodparam"><span class="type">int</span> <tt class="parameter">$blue</tt></span> , <span class="methodparam"><span class="type">int</span> <tt class="parameter">$alpha</tt></span> )</div> <p class="para rdfs-comment"> Returns the index of the specified color+alpha in the palette of the image. </p> </div> <div class="refsect1 parameters"> <h3 class="title">Parameters</h3> <p class="para"> <dl> <dt><span class="term"><i><tt class="parameter">image</tt></i></span><dd><p class="para">An image resource, returned by one of the image creation functions, such as <a href="function.imagecreatetruecolor.html" class="function">imagecreatetruecolor()</a>.</p></dd></dt> <dt> <span class="term"><i><tt class="parameter">red</tt></i></span> <dd> <p class="para"> Value of red component. </p> </dd> </dt> <dt> <span class="term"><i><tt class="parameter">green</tt></i></span> <dd> <p class="para"> Value of green component. </p> </dd> </dt> <dt> <span class="term"><i><tt class="parameter">blue</tt></i></span> <dd> <p class="para"> Value of blue component. </p> </dd> </dt> <dt> <span class="term"><i><tt class="parameter">alpha</tt></i></span> <dd> <p class="para"> A value between <i>0</i> and <i>127</i>. <i>0</i> indicates completely opaque while <i>127</i> indicates completely transparent. </p> </dd> </dt> </dl> The colors parameters are integers between 0 and 255 or hexadecimals between 0x00 and 0xFF. </p> </div> <div class="refsect1 returnvalues"> <h3 class="title">Return Values</h3> <p class="para"> Returns the index of the specified color+alpha in the palette of the image, or -1 if the color does not exist in the image's palette. </p> </div> <div class="refsect1 examples"> <h3 class="title">Examples</h3> <div class="example"> <p><b>Example #1 Get colors from the GD logo</b></p> <div class="example-contents"><div class="phpcode"><code><span style="color: #000000"><span style="color: #0000BB"><?php<br /><br /></span><span style="color: #FF8000">// Setup an image<br /></span><span style="color: #0000BB">$im </span><span style="color: #007700">= </span><span style="color: #0000BB">imagecreatefrompng</span><span style="color: #007700">(</span><span style="color: #DD0000">'./gdlogo.png'</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">$colors </span><span style="color: #007700">= Array();<br /></span><span style="color: #0000BB">$colors</span><span style="color: #007700">[] = </span><span style="color: #0000BB">imagecolorexactalpha</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">, </span><span style="color: #0000BB">255</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$colors</span><span style="color: #007700">[] = </span><span style="color: #0000BB">imagecolorexactalpha</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">, </span><span style="color: #0000BB">0</span><span style="color: #007700">, </span><span style="color: #0000BB">127</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$colors</span><span style="color: #007700">[] = </span><span style="color: #0000BB">imagecolorexactalpha</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">, </span><span style="color: #0000BB">255</span><span style="color: #007700">, </span><span style="color: #0000BB">255</span><span style="color: #007700">, </span><span style="color: #0000BB">255</span><span style="color: #007700">, </span><span style="color: #0000BB">55</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$colors</span><span style="color: #007700">[] = </span><span style="color: #0000BB">imagecolorexactalpha</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">, </span><span style="color: #0000BB">100</span><span style="color: #007700">, </span><span style="color: #0000BB">255</span><span style="color: #007700">, </span><span style="color: #0000BB">52</span><span style="color: #007700">, </span><span style="color: #0000BB">20</span><span style="color: #007700">);<br /><br /></span><span style="color: #0000BB">print_r</span><span style="color: #007700">(</span><span style="color: #0000BB">$colors</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">// Free from memory<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 class="example-contents"><p>The above example will output something similar to:</p></div> <div class="example-contents"><pre><div class="cdata"><pre>Array( [0] => 16711680 [1] => 2130706432 [2] => 939524095 [3] => 342163252)</pre></div> </pre></div> </div> </div> <div class="refsect1 notes"> <h3 class="title">Notes</h3> <blockquote><p><b class="note">Note</b>: <span class="simpara">This function requires GD 2.0.1 or later (2.0.28 or later is recommended).</span></p></blockquote> </div> <div class="refsect1 seealso"> <h3 class="title">See Also</h3> <p class="para"> <ul class="simplelist"> <li class="member"><a href="function.imagecolorclosestalpha.html" class="function" rel="rdfs-seeAlso">imagecolorclosestalpha()</a></li> </ul> </p> </div></div><hr /><div style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="function.imagecolorexact.html">imagecolorexact</a></div> <div class="next" style="text-align: right; float: right;"><a href="function.imagecolormatch.html">imagecolormatch</a></div> <div class="up"><a href="ref.image.html">GD Functions</a></div> <div class="home"><a href="index.html">PHP Manual</a></div></div></body></html>⌨️ 快捷键说明
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