What does the "Pixel Perfect" option do?

[Cyber Akuma]

Does this option disable any kind of stretching or filters or whatever.... or does it actually enable it? Or does it do something else entirely?

[Spectrum Legacy]

In general it means that pixels are nice and square (on lcd at least), without any stretching or warping. Pretty much means that the proportions are just as god intended.

How exactly it behaves in this game, I cannot say, but it shouldn't be far from the general description.