what is unsharp masking
SHARPENING: UNSHARP MASK. An unsharp mask is actually used to sharpen an image, contrary to what its name might lead you to believe. Sharpening can help you emphasize texture and detail, and is critical when post-processing most digital images.t turns out that an unsharp mask is actually utilizing a trick performed by our own human visual system. The human eye sees what are called Mach bands at the edges of sharp transitions, named after their discovery by physicist Ernst Mach in the 1860's. These enhance our ability to discern detail at an edge.