>>31056
I'm going to call that's it at best a photo painted over rather than filtered.

>>31057
I guess I should have mentioned that as a third option. Oh well.

Best way to tell if something is filtered or not is to look for dark spots. These are caused by the filter getting confused about where to place outlines. Uneven and out of place outlines are another give away. Spotty uneven shifts from one color to a slightly different shade can also be a give away. Stuff that's draw/painted will general have more even color transitions, unless it's on something like a tree where that's done on purposes to create the look of leafs.

>>31062
i wonder how often chinese tourist thinks thats a public toilet and poops in it?

>>31067
I'd wager about as often as American tourist assume it's a public water fountain and poop in it.

Sad news for background enthusiasts
https://blog.sakugabooru.com/2017/02/03/background-art-company-atelier-bwca-closing-down/
I didn't realize that there was a studio that only does backgrounds...

>>37859
This is old news from 2017, but sad news nonetheless, yeah. Regarding background art studios, there's actually a fair few of them (do note that some of these are just art departments of existing companies, though): https://anidb.net/tag/534