HP (Hewlett-Packard) 7400C Series Scanner User Manual


 
50 Scanning from HP PrecisionScan Pro Back to TOC
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Changing black-and-white threshold only applies to images using the
Black & White Bitmap output type. The threshold is a value in the
image that represents the border between black and white. All values
in the image that are lighter than the threshold appear as white, and all
values darker appear as black.
The image has a default threshold value. Choosing a number closer to
zero makes more values appear as white. Choosing a higher number
makes more values appear as black.
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1 Make sure that Black & White Bitmap is selected on the Output
Type menu. The selection should have a dot beside it.
2 On the Advanced menu, click Adjust Black & White Threshold.
3 Do one of the following:
Drag the slider.
Type a new value in the field and press ENTER.
Click the Up or Down arrow next to the field.
4 If necessary, sharpen the image. This can be especially useful if
the original was a color or black-and-white photograph. See
"Sharpening an image" on page 40.
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1 On the Advanced menu, click Adjust Black & White Threshold.
2 Click Auto.
Threshold at 127
(the default for this image)
Threshold at 45