I recently got interested in algorithms for scaling pixel art images, such as icons or video game sprites. The Wikipedia page on the topic lists a handful of different algorithms that have been developed for that purpose.
Obviously, it would be interesting to compare the results of different algorithms, and to apply them to one’s own graphics problems. But I could not find a readily available tool or library, only scattered implementations here and there. Some algorithms have only been proposed in forum discussions, which at this point are only available via the Wayback Machine or a comparable archive.
I therefore collected the implementations that I could find, augmented them with implementations of my own where necessary, and combined them into one handy tool. Find it, together with a gallery of examples, on github.