Canon FB630U/FB636U - Manual (Page 22)

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S T E P 1
When an image is scanned, it is read as a collection of “dots.” The scan mode that is
selected determines how each of these dots is represented in the output. The following
five scan modes are available.
Black & White
Displays each dot as either black or white. Grays and halftones are also reproduced
as black or white. The Black & White mode is best for documents that contain text
and line drawings and not suited for images with color gradations.
Diffusion Dither
Displays each dot as either black or white. In order to create gray tones this method
uses randomly dispersed black dots on white to create a more natural looking
gradation.
Grayscale
In the Grayscale mode, each dot is formed by assigning it eight individual “bits” of
data. By combining these bits in various different ways, a dot can be expressed in over
256 distinct shades. Photographic images are reproduced relatively naturally in this
mode, but the file size is much larger than that produced by the Black & White mode.
Set Scan Mode
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