optipng software package provides advanced PNG (Portable Network Graphics) optimizer, 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 optipng
optipng is installed in your system.
Make ensure the optipng package were installed using the commands given below,
$ sudo dpkg-query -l | grep optipng *
You will get with optipng package name, version, architecture and description in a table
| Distro | Ubuntu 14 04 lts trusty tahr |
| Section | Graphics |
| Package | optipng |
| Version | 0.6.4-1ubuntu0.14.04.1 [amd64, |
| Description | advanced PNG (Portable Network Graphics) optimizer |
| Sub Section | Graphics |