$ sudo apt-get remove gif2png 

Uninstall gif2png including dependent package

If you would like to remove gif2png and it's dependent packages which are no longer needed from Ubuntu,

$ sudo apt-get remove --auto-remove gif2png 

Use Purging gif2png

If you use with purge options to gif2png package all the configuration and dependent packages will be removed.

$ sudo apt-get purge gif2png 

If you use purge options along with auto remove, will be removed everything regarding the package, It's really useful when you want to reinstall again.

$ sudo apt-get purge --auto-remove gif2png 

See Also,