On Mon, Jan 04, 2021 at 10:37:34PM +0100, Frank Steinmetzger wrote > > When I edit photos, I like to shrink and recompress them to save on > space, but not mangle them too much in the process to lose quality.
Actually, shrinking *BY AN INTEGER NUMBER SHOULD IMPROVE QUALITY* as well as saving space. In Google look up the phrase... photography binning adjacent pixel If you bin a 3840x2160 image by 2, you'll get a 1920x1080 result. If you bin it by 3, you'll get 1280x720 image. The math is a bit convoluted, but when you bin by a value of "n"... * the information per combined pixel increases by a factor of "n" * the noise per combined pixel increases by a factor of square root of "n" So the "signal-to-noise-ratio" increases. The resulting image is less noisey. The tradeoff is that the new image is smaller than the original. I use the imagemagick "convert" utility from the commandline, but any capable image software should work. -- Walter Dnes <waltd...@waltdnes.org> I don't run "desktop environments"; I run useful applications
