Multipliers higher than 2x

[Atemu]

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Currently, Anime4K offers 2x scaling which is a perfect fit for upscaling 1080p content to 2160p or 720p to 1440p.

There is no option to upscale by a factor of e.g. 3x or 4x though. These would be useful for e.g.:

480 -> 1440
720 -> 2160
360 -> 1440

480 -> 1440 would be the most useful one as 480p is the lowest resolution you usually find anime in and 1440p is the new gold standard for computer monitors. It might also potentially be useful for downsampling to 1080p as that might look better than upsampling from 2x' 960p.

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Shaders for scaling >2x.

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Use 2x two times and optionally downscale that for "3x" perhaps?

Not sure whether a) scaling twice produces the same (or better?) result as one 4x step and b) downsampling 4x would look as good as 3x.

I imagine both would be worse than direct conversion performance-wise.

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