GD is an open source code library for the dynamic creation of images by programmers. GD creates PNG, JPEG and GIF images, among other formats. GD is commonly used to generate charts, graphics, thumbnails, and most anything else, on the fly. While not restricted to use on the web, the most common applications of GD involve web site development.
1. sudo apt-get install php5-gd
2. sudo /etc/init.d/apache2 restart
You should now have GD support!