Turn a favourite picture into a crisp 4K desktop background
A 4K monitor or TV exposes every soft pixel in a small image. Upscaling your photo or artwork to 3840×2160 makes a 4K wallpaper that fills the screen without looking stretched.
Choosing a source for a 4K wallpaper
The best results come from images that are already at least 1920 pixels wide. The 1080p to 4K preset doubles each side exactly, which is the cleanest possible 4K wallpaper upscale. Very small images can be enlarged too, but they will look softer.
Photos vs artwork
Use Lanczos with moderate sharpness for landscapes and photos; use Deep Enhance for anime or illustrated wallpapers.
Phone wallpapers
Crop to your phone's aspect ratio first, then upscale 2× for high-density screens.