SmartUpscale — author’s Firefox extension
SmartUpscale is a new author’s Firefox web-browser extension that prevents blurring images which have their size in physical pixels an integer number of times larger than their natural size, i. e. each image pixel can be represented as a group of same-color physical pixels (2×2, 3×3, etc.).
The extension may be useful when using high-DPI monitors, including 4K monitors used at OS-level zoom of 200%.
Extension’s options allow to limit maximum image zoom (not to be confused with page zoom) that blur should be prevented at (by default, there is no limitations), and to disable blur globally if needed.