Say I wanted to take a data file (like an excel file), and display it as an image. I would imagine that it would just look like a bunch of white noise, but I've always been curious to see what kind of patterns develop. I've already converted some excel files and other files to audio in the past, so I've listened to pictures and spreadsheets. Anyway, how would I go about opening a file in a format that wouldn't cause an error (e.g. "This is not a valid .jpg format"). May a RAW? Or BMP?
Quick test to see if they might look like white noise: try compressing them -- if they don't compress very much at all, they will probably look very noisy.
If know a programming language, converting them to a bmp would be easy as it has a simple format.