[johncostella]

The paper includes examples of Magic Kernel Sharp 3 (the original), 4, 5, and 6. The C code allows you to use any value 'a' of these "generations," and any version 'v' of the Sharp kernel listed in the paper (up to a = 6, v = 7), for any case you want to try. I may add more versions later.

The Sharp+ is just extra sharpening. It's included in the executable, but isn't fundamentally anything more than extra sharpening over what tries to be as-close-to-ideal resizing as possible.

[jchw]

Ahh, that would make sense; it didn’t occur to me to check the paper. I was mostly curious to see at a glance how it would visually compare with the addition of sharpening. Ultimately, it ends up looking pretty good.

[johncostella]

Yes, and if you're comfortable pulling down the code and running 'make' on any *nix system, there is an executable 'resize_image' that lets you test it out for yourself. I'm always looking out for corner cases that stress-test the differences between the algorithms, so let me know if you find any good ones.