Uploading a URL of white noise from Wikipedia gave it a high-memorability (0.82) with lots of areas of interest. Secondly uploading a purely white image [2] produced high areas of interest in the top corners and a mediumly interesting image (0.62).

I thought the tests might reveal something useful, like the eye-tracking heat-maps of Jakob Nielsen [3] but I'm not convinced.

[1] https://upload.wikimedia.org/wikipedia/commons/f/f6/White-no...

[2] http://images.all-free-download.com/images/graphiclarge/plai...

[3] https://www.nngroup.com/books/eyetracking-web-usability/