So I was reading the BBC news website which has an article on GCHQ’s Christmas card.

This led me to wonder what is was as I hadn’t seen one before, it turns out it is a nonogram or picross. Then it suddenly hit me, this is a form of run length encoding, that we will be covering later in the course. It’s just that in this case the encoding is only for black squares. Anyway I just wanted to share it now while it was topical.