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English
In web development, dynamically generated images are often used to display advertising banners, verification codes, charts and other contents. PHP provides rich image processing functions, where imagecreatefromgd2() can create an image resource from an image file in .gd2 format. This article will introduce how to use the imagecreatefromgd2() function to generate a dynamic banner image and output it to a web page.
GD2 is an image format of the GD library that can store more complex image data. It is not a common image format (such as JPG or PNG), but the GD2 format has good loading performance and is suitable for fast image processing on the server side.
resource imagecreatefromgd2 ( string $filename )
This function takes a .gd2 file path as a parameter and returns an image resource. If the file does not exist or is incorrect in format, false will be returned.
The following example shows how to read an image from a .gd2 file and add text dynamically, and finally display it as a banner on a web page.
<?php
// Set the content type to PNG picture
header('Content-Type: image/png');
// Read GD2 Image Resources
$img = imagecreatefromgd2('banner_template.gd2');
if (!$img) {
die('Unable to load GD2 Image File');
}
// Set font color（White）
$white = imagecolorallocate($img, 255, 255, 255);
// Set font size and angle
$fontSize = 5;
$x = 20;
$y = 20;
// Add custom text
$text = "Welcome to visit m66.net";
imagestring($img, $fontSize, $x, $y, $text, $white);
// Output image to browser
imagepng($img);
// 释放Image Resources
imagedestroy($img);
?>
You can save this script as banner.php and then embed the dynamically generated banner image on the web page as follows:
<img src="https://m66.net/banner.php" alt="dynamic Banner">
Every time you access banner.php , the server will dynamically read the .gd2 template image and add custom text to output it as a PNG image.
banner_template.gd2 file must exist and be in a PHP readable path.
GD2 images do not support generation of all image editing tools, and it is recommended to use PHP's imagegd2() function to create them.
This method is suitable for scenes that do not require frequent updates but require personalized display.
imagecreatefromgd2() is a powerful function provided by PHP to create resources from GD2 format images. Combining imagestring() and other GD functions, dynamic content images can be easily generated, such as personalized banners. With appropriate caching control and secure processing, it can also be applied to real web projects to enhance the user experience.
Do you need me to help you generate a sample GD2 image file or an introduction to the extension function?
