If you plan to use php to process some images, you should make PHP GD library enable, to make it enable you can do like this.
Step 1: Check it enable?
You can create a php file and paste code below, then open it by your browser.
<?php phpinfo(); ?>
If you find result like below, you can be sure PHP GD library enable has been enable in your php develope evironment, and you can use it to process some images. If not, you can read step 2.
Pages: 1 2
Related Posts
2 Steps to convert png into ico with phpthumb in php
2 Steps run php script by command line in window system
4 Steps to run php script in your computer
2 Steps to know whether vistors use mobile to visit your website in PHP
2 Steps to use http referer in php
2 Steps to visit google plus in china by editing hosts file 
2 Steps to create QR code by google api and php
2 Steps to create your circle in google plus