Microtek ScanWizard EZ Reference Manual page 103

Sharpen Low/Sharpen Medium/Sharpen High
The Sharpen filters do the opposite of the Blur filters and increase the contrast
of adjacent pixels, making images appear sharper and more focused.
The three sharpening filters (Sharpen Low , Sharpen Medium, and Sharpen High)
improve clarity. The Sharpen High filter has a greater sharpening effect than the
Sharpen Medium filter, which in turn has a greater sharpening effect than the
Sharpen Low filter.
Sharpen High Unsharp Masking
Unsharp Masking
The Unsharp masking filter is used to adjust the contrast of edge detail, creating
the illusion of more image sharpness. This filter can be useful for refocusing an
image that has become blurry from interpolation or scanning, and it is an
essential tool for doing CMYK color separation. In general, Unsharp masking is
needed to render sharp color reproductions, especially when you wish to make
a large color reproduction from a small original.
Microtek ScanWizard EZ - Professional Mode Reference Manual 63