Thank you for making this software available, it enabled me to be able to view a large image of an Ulam Spiral which I had no other way of visualising. It's probably not quite what the software was designed for but it worked a treat :-)
Below is a link to the 10 Gigapixel image... zoomed in to start with because it's quite featureless when zoomed out:
10 Gigapixel Ulam Spiral