Microtek 120tf 参照マニュアル

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102          Microtek ScanWizard Pro TX for Mac & PC
This parameter specifies a
tolerance range to prevent
overall sharpening that
might generate noise or
cause unexpected results.
The Threshold defines the
required range of contrast
between adjacent pixels
before Unsharp Masking is
applied to edges.
 A lower Threshold value
produces a more
pronounced effect.
Dark pertains to how the
Unsharp Masking filter
affects pixels which are
darker than their adjacent
pixels. By default, a value of
100 is specified for this field.
The higher the value, the
darker the edge around the
lighter areas and the more
pronounced the Unsharp
Masking effect is.
If both values Light & Dark
parameters are 0, Unsharp
Masking is disabled
Mask Size determines the
depth of surrounding pixels
that will affect the edges.
The larger the mask size, the
stronger the sharpening
effect of the filter.
Strength  specifies the
degree of the filter's effect
here. The higher the value,
the stronger the sharpening
effect of the filter. Too much
USM will emphasize the noise
in the image.
Light pertains to how the Unsharp
Masking filter affects pixels which are
lighter than their adjacent pixels. By
default, a value of 60 is specified for this
field. The higher the value, the lighter the
edge around the darker areas and the
more pronounced the Unsharp Masking
effect is.
In general, too much Unsharp Mask on
light edges would make the image looks
unnatural due to sensitivity of human
vision toward bright image area. If both
values Light & Dark parameters are 0,
Unsharp Masking is disabled
Original
Unsharp Masking 5x5 mask
size
Unsharp Masking 3x3 mask
size
Unsharp Masking (USM) filter
The Unsharp Masking (USM) filter adjusts the contrast of edge detail and creates
the illusion of more image sharpness. This filter can be useful for refocusing an
image that has become blurry from interpolation or scanning. The dialog box
below appears when you choose Unsharp Masking from the Filters menu. It is
an essential tool for doing CMYK color separation.  In general, Unsharp Mask is
needed to make a good sharpness color reproduction, especially when you want
to make a large color reproduction from a small original such as slides.