MMPX
MMPX Style-Preserving Pixel Art Magnification (c99 version) https://casual-effects.com/research/McGuire2021PixelArt/index.html
This code is from the C++ benchmark example, just slightly modified for C. MIT licensed.
Examples
Few examples taken from my SMS emulator.
Left is nearest x2, right is MMPX x2.
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