Binary Scanning-Threshold - Ricoh IS01 Operator's Manual

SCANNER FEATURES
Binary Scanning - Threshold
Function Binary scanning converts every pixel included in the image to either
black or white. When the image contains a gray area, the threshold
value determines whether the scanner records the area as black or
white. When the threshold value is high, the scanner records more
pixels as black. When the threshold value is low, the scanner
records fewer pixels as black.
Usage Use a binary composition when you want to scan binary images
such as text and line drawings, or black and white images that have
no gray areas.
You can use either the manual threshold or the dynamic threshold
method to set the threshold value in binary scanning.
Manual threshold
An entire image is converted to binary using a specific threshold. You can
set a threshold value between 1 and 255. When scanning a light image, set
the threshold higher. When scanning a dark image, set the threshold lower.
Original image
Lower threshold
A-4
Higher threshold
Higher threshold