PNG creation with PHP
Examples
PNG creation with PHP
PNG creation with PHP
<?php
header("Content-type: image/png");
$string = $_GET['text'];
$im = imagecreatefrompng("images/button1.png");
$orange = imagecolorallocate($im, 220, 210, 60);
$px = (imagesx($im) - 7.5 * strlen($string)) / 2;
imagestring($im, 3, $px, 9, $string, $orange);
imagepng($im);
?>This example would be called from a page with a tag like: <img src="button.php?text=text">. The above button.php script then takes this "text" string and overlays it on top of a base image which in this case is "images/button1.png" and outputs the resulting image. This is a very convenient way to avoid having to draw new button images every time you want to change the text of a button. With this method they are dynamically generated.
Adding watermarks to images using alpha channels
Adding watermarks to images using alpha channels
<?php
// Load the stamp and the photo to apply the watermark to
$stamp = imagecreatefrompng('stamp.png');
$im = imagecreatefromjpeg('photo.jpeg');
// Set the margins for the stamp and get the height/width of the stamp image
$marge_right = 10;
$marge_bottom = 10;
$sx = imagesx($stamp);
$sy = imagesy($stamp);
// Copy the stamp image onto our photo using the margin offsets and the photo
// width to calculate positioning of the stamp.
imagecopy($im, $stamp, imagesx($im) - $sx - $marge_right, imagesy($im) - $sy - $marge_bottom, 0, 0, imagesx($stamp), imagesy($stamp));
// Output
header('Content-type: image/png');
imagepng($im);
?>Adding watermarks to images using alpha channels
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.
Using imagecopymerge() to create a translucent watermark
Using imagecopymerge() to create a translucent watermark
<?php
// Load the stamp and the photo to apply the watermark to
$im = imagecreatefromjpeg('photo.jpeg');
// First we create our stamp image manually from GD
$stamp = imagecreatetruecolor(100, 70);
imagefilledrectangle($stamp, 0, 0, 99, 69, 0x0000FF);
imagefilledrectangle($stamp, 9, 9, 90, 60, 0xFFFFFF);
imagestring($stamp, 5, 20, 20, 'libGD', 0x0000FF);
imagestring($stamp, 3, 20, 40, '(c) 2007-9', 0x0000FF);
// Set the margins for the stamp and get the height/width of the stamp image
$marge_right = 10;
$marge_bottom = 10;
$sx = imagesx($stamp);
$sy = imagesy($stamp);
// Merge the stamp onto our photo with an opacity of 50%
imagecopymerge($im, $stamp, imagesx($im) - $sx - $marge_right, imagesy($im) - $sy - $marge_bottom, 0, 0, imagesx($stamp), imagesy($stamp), 50);
// Save the image to file
imagepng($im, 'photo_stamp.png');
?>Using imagecopymerge() to create a translucent watermark
This example uses imagecopymerge() to merge the stamp with our original image. Using this we can set the opacity of our stamp - in our example we've set it to 50% opacity. In practice this would be useful in copyright protection as semi-transparent watermarks are hard to remove yet allow viewers to see the image.