SIR (Simple Image Resizer) is a tool written in C++/QT that allows users to batch convert and resize images of different formats (JPEG, PNG, BMP, GIF, XPM, PGM, PBM, and PPM) under Ubuntu. You can also use SIR to rotate your images. In this brief guide we will help you install SIR on Ubuntu 11.10/11.04, you can also install it on older versions of Ubuntu (10.10/10.04).
To install SIR on Ubuntu 11.10/11.04, run these commands from the Terminal:
sudo add-apt-repository ppa:rsachetto/ppa
sudo apt-get update
sudo apt-get install sir
Launch SIR using the Unity Dash and click Add File or Add Dir to start resizing your images to any dimensions of your choice.