Do you have hundreds of images and want to resize them all to a specific resolution? Instead of resizing each image separately, you can simply use RedImages, which is a lightweight and fast program that allows users via a simple GUI to batch resize images to any resolution they want. In this page we will help you install RedImages under Ubuntu 11.10/12.04 via PPA.
Open the terminal and run these commands:
sudo add-apt-repository ppa:upubuntu-com/graphics
sudo apt-get update
sudo apt-get install redimages
RedImages can be then started via the Unity Dash:
Or run this command from the terminal:
You can find the home page for RedImages here.