Microtek ArtixScan 4500t Reference Manual page 94

You can use the Black and White Eyedropper tools to define the Shadow and
Highlight points.
To do this: Click the Eyedropper tools in the White & Black Points dialog box.
Then move to the thumbnail image in the dialog box or to the preview image in
the Preview window, and choose your Black / White Point.
• To define the Black (shadow) point, use the Black Eyedropper tool.
• To define the White (highlight) point, use the White Eyedropper tool
The shadow point is defined as the lightness value "L" in an image that is output as black
(mapped to the Minimum Output Level), while the highlight point is defined as the lightness
value "L" that is output as white (mapped to the Maximum Output Level).
The default values of the Minimum Output Level and Maximum Output Level are L=5.0 and
L=95.0, respectively.
Black Eyedropper to
define the Shadow
point
Reference: The Advanced Image Correction tools
Enable this check
box to show the
adjustment effect
on the prescan
image
White Eyedropper
to define the
Highlight point
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