unsharp
verbEtymology From Middle English *unscharp, from Old English unsċearp, from Proto-West Germanic *unskarp, from Proto-Germanic *unskarpaz, equivalent to un- + sharp. Cognate with Saterland Frisian uunskäärp (“unsharp”), West Frisian ûnskerp (“unsharp”), Dutch onscherp (“unsharp”), German Low German unscharp (“unsharp”), German unscharf (“unsharp”), Danish uskarp (“unsharp”), Swedish oskarp (“unsharp”), Norwegian uskarp (“unsharp”).
Computer graphics, Computing, Engineering, Mathematics, Natural sciences, Physical sciences, Sciences To sharpen (an image) by creating a blurred ("unsharp") negative as a mask, and then combining that mask with the original.