The brightness of color and grayscale images is expressed in a value between 0 and 255. However, in creating black and white images, all colors are mapped to either black (0) or white (255). "Threshold" is the borderline value that determines a color as black or white. By adjusting the threshold level, you can sharpen text in a document or reduce show-through in newspapers.
This function is available when Color Mode is Black and White.
In ScanGear (scanner driver)'s Advanced Mode tab, click 
(Threshold).
NoteClick Defaults to reset all adjustments in the current window.
Move 
(Slider) to the right to increase the threshold value and thus increase the black areas. Move the slider to the left to decrease the value and thus increase the white areas. You can also enter a value (0 to 255).
