Background briefing – images and social media
We'll use the Pillow implementation of the PIL package to extract and convert any graphics or images. In Chapter 1, New Missions, New Tools, we used the pip3.4 program to install Pillow 2.9.0. The PIL package has modules that allow us to convert images to a common format. It also allows us to create thumbnails of images. This can help us build a tidy summary of images we collected.
Most importantly, it allows us to validate an image file. It turns out that the compression algorithms used on some images can be hacked. Someone can tweak the bytes of an image so that it appears to be infinitely large. This will cause the computer opening the image to get progressively slower until the image processing application finally crashes. A basic counter-intelligence ploy is to circulate damaged image files that leave agents struggling to figure out what went wrong.
The PIL module is an important piece of counter-counter-intelligence. We don...
