pngcrush software package provides optimizes PNG (Portable Network Graphics) files, 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 pngcrush
pngcrush is installed in your system.
Make ensure the pngcrush package were installed using the commands given below,
$ sudo dpkg-query -l | grep pngcrush *
You will get with pngcrush package name, version, architecture and description in a table
| Distro | Ubuntu 14 04 lts trusty tahr |
| Section | Graphics |
| Package | pngcrush |
| Version | 1.7.65-0.1 |
| Description | optimizes PNG (Portable Network Graphics) files |
| Sub Section | Graphics |