Xerox DocuMate 3220 - Page 174

Xerox
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DocuMate
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3220
User’s Guide
174
Error diffusion, Bayer, and Halftone pattern
Error diffusion
, Bayer, and Halftone patterns are the intentional application of noise (dithering) in the
image to help alleviate banding when scanning in binary (black and white) mode. For example, if you
scan a color photo in black and white, the image file will have large blocks of black and white and the
image barely recognizable. Dithering the image creates a black and white image that is recognizable.
Below is an example of a color scan, a black and white scan without dithering, and a black and white
scan with dithering. When the image is scaled down, it may look like a grayscale scan. When the image
is at normal size or enlarged you will be able to clearly see the dithering pattern, as shown in the close-
up image.
Bayer dither scan - Close up
Color scan
Black and White scan Bayer dither scan