I saw someone do something similar in ye olde days of Gravatar. It abused their resizing algorithm to get different images at different scales. It was very si

I saw someone do something similar in ye olde days of Gravatar. It abused their resizing algorithm to get different images at different scales. It was very simple (and probably couldn't have worked if it was much more complicated) - just the text `i++` on a noisy background. But when scaled it turned into `i--`. In both cases, it was very readable.