Avision IS25 manual - Manual (Page 67)

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
5-23