$ sudo apt-get remove gthumb-data 

Uninstall gthumb-data including dependent package

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

$ sudo apt-get remove --auto-remove gthumb-data 

Use Purging gthumb-data

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

$ sudo apt-get purge gthumb-data 

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 gthumb-data 

See Also,