The first 30 seconds of this may not catch your attention, but stick with it. Here's the basic idea:
If you have an image that's too big for the space you have to display it, the two main options are to scale the image down, making everything smaller, or to crop the edges off of the image to make it fit. This video is a demo of an alternative method, where the important parts of the image are kept as-is, and the unimportant parts are cut out.
(via O'Reilly Radar)