Install Photivo (Ubuntu PPA), An Open and Free Photo Processor for Linux

Photivo is not a re-placer for Gimp by any means. It actually is not a photo editor but a processor. So if you have RAW images that need little processing, like adding denoise, cropping, change hue or brightness, sharpen, and various other filters, etc.... then Photivo is for you.

It actually has a Gimp integration, so you can import and export your edited pictures in Gimp to Photivo for processing. So if you have installed ubuntu and this is how you install it using PPA...

Open a terminal and issue the below commands

sudo add-apt-repository ppa:dhor/myway
sudo apt-get update
sudo apt-get install photivo