Original details are at http://www.sublimetext.com/~jps/animated_gifs_the_hard_way.html
sudo apt-get install pngcrush python-opencv python-numpy python-scipy python anim_encoder.py example firefox example.html
Images will be saved to capture, you simply need to run capture.py and then go about your task. Note you can just delete frames you don't want as you initially set up, should save you some time. Then to run the program just go
If you need to change any settings it should be pretty simple just jump over to config.py and edit the configuration options.