Embedding Pictures in Music

I once asked a friend of mine in uni if it was hard to write a program that generates audio from image files after listening to aphex twin.. Later that day he had this completed: http://134.74.16.64/wwwa/web/hardware/soundmural/

edit: since then, i've researched more on the topic, on signal decomposition and transforms and understand this a lot better :)

Here is the spectrogram, and some others. http://www.bastwood.com/aphex.php