Microtek ScanMaker 6100 Pro User Manual page 83

For Line Art images, the Brightness & Contrast screen becomes the
Threshold setting, and the Threshold dialog box appears instead.
Threshold is the dividing line between black and white; the range is
0 to 255, and the default is 128. Thus, gray levels below the
Threshold are converted to black, while gray levels equal to or
above the Threshold are converted to white, resulting in a high-
contrast, black-and-white representation of the image.
Before
Using the Threshold feature:
1. Drag the sliders to change the Threshold.
To darken the original, drag the slider
This increases the Threshold value so that more pixels
are turned to black, resulting in a darker image.
To lighten the original, drag the slider
lowers the Threshold value so that more pixels are turned
to white, resulting in a lighter image.
2. Alternatively, you can enter a value in the Threshold edit box
to change the Threshold.
3. The Sharpen option lets you sharpen the Line Art image.
After
to the right.
to the left. This