看到「Anime4K」這個專案：
Anime4K is a state-of-the-art*, open-source, high-quality real-time anime upscaling algorithm that can be implemented in any programming language.
State of the art* as of August 2019 in the real time anime upscaling category, the fastest at acheiving reasonable quality. We do not claim this is a superior quality general purpose SISR algorithm compared to machine learning approaches.
他們提供的數據顯示 1080p -> 2160p (4K) 只要 3ms，對於 60fps 來說是相當足夠，而品質看起來也還不錯。
其中一個蠻有趣的問答是 1080p -> 2160p 反而比 480p -> 720p 簡單，因為 1080p 裡面因為有更多資料量，所以處理起來比較簡單：
Why not do PSNR/SSIM on 480p->720p upscaling
Story TimeComparing PSNR/SSIM on 480p->720p upscales does not prove and is not a good indicator of 1080p->2160p upscaling quality. (Eg. poor performance of waifu2x on 1080p anime) 480p anime images have a lot of high frequency information (lines might be thinner than 1 pixel), while 1080p anime images have a lot of redundant information. 1080p->2160p upscaling on anime is thus objectively easier than 480p->720p.