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5.3
The Compression Tab
The Compression tab allows you to compress your scanned
image and choose the level of compression. Bi-tonal images
are normally compressed using CCITT standard called Group 4
(G4). Color and grayscale images are often compressed using
JPEG technology. Move the JPEG Quality slider to the right or
left to increase or decrease the level of compression. Note the
greater the compression level, the lower image quality. Default
is 50%.
Note that the compression depends on your image editing
application. If your image editing application does not support
the type of compression format, then either a warning
message will appear or the image quality of the compressed file
will not be acceptable.
JPEG (Joint Photographic Editor Group). This group developed
and lent their name to a file compression standard for color and
grayscale images that is widely used by scanners, and software
applications. On Microsoft Windows-based systems, a file with
the extension .jpg has normally been compressed using this
standard.
For scanning color or gray images, the following compressions
are available:
y
None
y
JPEG
For scanning B&W images, the following compressions are
available:
y
None
y
G4
