[动漫国字幕组&VCB-Studio] Tenki no Ko / 天气之子 / 天気の子 10-bit 1080p 2160p HEVC BDRip [MOVIE Fin][bt磁力种子](4)

In our analysis, though, it does appear that the line art is somewhat characteristic of an 1080p upscale, but we could also see some still recognizable character strokes in the background, while they"re blended in the 1080p version，so we guess the original resolution of the master used for the 2160p version is probably a bit higher than 1080p, but still much lower than 2160p.
After a few rounds of trial and error, we decided to use the descaling and reconstruction method with a bicubic kernel that was able to smooth out most aliasing without losing too much sharpness, and then applied strong de-ringing to clean up the surroundings. These processing do cause some loss of sharpness and minor artifacts, but the result should still look much better than the source.