<!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>Adding watermarks to images using alpha channels</title> </head> <body><div class="manualnavbar" style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="image.examples-png.html">PNG creation with PHP</a></div> <div class="next" style="text-align: right; float: right;"><a href="image.examples.merged-watermark.html">Using imagecopymerge to create a translucent watermark</a></div> <div class="up"><a href="image.examples.html">Examples</a></div> <div class="home"><a href="index.html">PHP Manual</a></div> </div><hr /><div id="image.examples-watermark" class="section"> <h2 class="title">Adding watermarks to images using alpha channels</h2> <p class="para"> <div class="example" id="example-3167"> <p><strong>Example #1 Adding watermarks to images using alpha channels</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">// Load the stamp and the photo to apply the watermark to<br /></span><span style="color: #0000BB">$stamp </span><span style="color: #007700">= </span><span style="color: #0000BB">imagecreatefrompng</span><span style="color: #007700">(</span><span style="color: #DD0000">'stamp.png'</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$im </span><span style="color: #007700">= </span><span style="color: #0000BB">imagecreatefromjpeg</span><span style="color: #007700">(</span><span style="color: #DD0000">'photo.jpeg'</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">// Set the margins for the stamp and get the height/width of the stamp image<br /></span><span style="color: #0000BB">$marge_right </span><span style="color: #007700">= </span><span style="color: #0000BB">10</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$marge_bottom </span><span style="color: #007700">= </span><span style="color: #0000BB">10</span><span style="color: #007700">;<br /></span><span style="color: #0000BB">$sx </span><span style="color: #007700">= </span><span style="color: #0000BB">imagesx</span><span style="color: #007700">(</span><span style="color: #0000BB">$stamp</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">$sy </span><span style="color: #007700">= </span><span style="color: #0000BB">imagesy</span><span style="color: #007700">(</span><span style="color: #0000BB">$stamp</span><span style="color: #007700">);<br /><br /></span><span style="color: #FF8000">// Copy the stamp image onto our photo using the margin offsets and the photo <br />// width to calculate positioning of the stamp. <br /></span><span style="color: #0000BB">imagecopy</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">, </span><span style="color: #0000BB">$stamp</span><span style="color: #007700">, </span><span style="color: #0000BB">imagesx</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">) - </span><span style="color: #0000BB">$sx </span><span style="color: #007700">- </span><span style="color: #0000BB">$marge_right</span><span style="color: #007700">, </span><span style="color: #0000BB">imagesy</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">) - </span><span style="color: #0000BB">$sy </span><span style="color: #007700">- </span><span style="color: #0000BB">$marge_bottom</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">imagesx</span><span style="color: #007700">(</span><span style="color: #0000BB">$stamp</span><span style="color: #007700">), </span><span style="color: #0000BB">imagesy</span><span style="color: #007700">(</span><span style="color: #0000BB">$stamp</span><span style="color: #007700">));<br /><br /></span><span style="color: #FF8000">// Output and free memory<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">$im</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">imagedestroy</span><span style="color: #007700">(</span><span style="color: #0000BB">$im</span><span style="color: #007700">);<br /></span><span style="color: #0000BB">?></span> </span> </code></div> </div> <div class="mediaobject"> <div class="imageobject"> <img src="images/21009b70229598c6a80eef8b45bf282b-watermarks.png" alt="Adding watermarks to images using alpha channels" width="320" height="240" /> </div> </div> </div> This example is a common way to add watermarks and stamps to photos and copyrighted images. Note that the presence of an alpha channel in the stamp image as the text is anti-aliased. This is preserved during copying. </p> </div><hr /><div class="manualnavbar" style="text-align: center;"> <div class="prev" style="text-align: left; float: left;"><a href="image.examples-png.html">PNG creation with PHP</a></div> <div class="next" style="text-align: right; float: right;"><a href="image.examples.merged-watermark.html">Using imagecopymerge to create a translucent watermark</a></div> <div class="up"><a href="image.examples.html">Examples</a></div> <div class="home"><a href="index.html">PHP Manual</a></div> </div></body></html>