Where is done image resizing/upscaling when a non native resolution is used on a LCD/IPS/OLED, any fixed resolution screen? Is it done by the OS, by its drivers, or by the monitor itself?
Let's say my laptop native resolution is 3840x2160, but I can choose 1920x1080 and it still looks reasonably good, despite the image is upscaled 2x! Slightly more blurry, but not necessarily in a bad way. As a matter of fact, I actually prefer that to the native resolution and frequently use it. Fonts appear less sharpy and I prefer it.
What filters are used? It's clearly something more complex then the simplest linear interpolation, because the results are too smooth for that. There may even use several filters, with some eventual resharpening applied. Where is this all done? Can I influence it somehow?
Side note: the reasons I frequently use non-native resolution is that my screen is HiDPI, so it needs scaling, the desktop scaling, and GUIs still have issues with it. Many apps still doesn't handle it at all or not without issues. Situation is even worse in Linux. Gnome doesn't handle fractional scaling; KDE requires restart when scaling is changed. Pain! It's so much easier to just change resolution.
