Waifu2x Libretro port and a shader-based version. about waifu2x

[nagadomi]

GLSL version can be found at https://github.com/ueshita/waifu2x-converter-glsl .
However, waifu2x filter is very slow. I think waifu2x is not suitable for shader in game.

[ADormant]

@nagadomi Okay I just found some optimized versions with AVX1/2 http://forum.videohelp.com/threads/372157-New-upscaling-algorithm-waifu2x .
https://github.com/lltcggie/waifu2x-caffe
https://github.com/MaverickTse/aviutl-waifu2x-gl
https://github.com/WL-Amigo/waifu2x-converter-cpp
Even if it is slow it's still worth it to give it a shot. RetroArch has dozens of different cores and not only gaming ones. Could you try to port it to RetroArch's shader spec?

[nagadomi]

I won't do it individually.

[ADormant]

Then I understand there're some technical difficulties? Well, maybe someone will notice this issue and try.

[leilei-]

realtime neural network scalers are no way feasible for gaming. At best it's for preprocessing textures not even at load time (like say, a replacement texture pack for upscaling drawn anime-style portaits in 2D PSP games, for example).

Also Waifu2x is not very good with pixel artwork. It's designed for repairing smooth and curvy manga strokes lost in resampling/compression. Applying it to pixel art will just give you mostly blockier pixels with a slight gradient to edged color blending.

[ADormant]

Well look at that serration reduction. hrydgard/ppsspp#7796