php5-gd software package provides GD module for php5, you can install in your Ubuntu 14.04 LTS (Trusty Tahr) by running the commands given below on the terminal,
$ sudo apt-get update $ sudo apt-get install php5-gd
php5-gd is installed in your system.
Make ensure the php5-gd package were installed using the commands given below,
$ sudo dpkg-query -l | grep php5-gd *
You will get with php5-gd package name, version, architecture and description in a table
| Distro | Ubuntu 14 04 lts trusty tahr |
| Section | PHP |
| Package | php5-gd |
| Version | 5.5.9+dfsg-1ubuntu4.20 [amd64, |
| Description | GD module for php5 |
| Sub Section | PHP |