Avision AVA3 400 - Manual (Page 38)

Scanner Operation
4-11
Gray (1024 levels gray scale/Internally)
A single-channel image consists of at least 256 levels of
shades of gray in an image. A 10 bits scanner produces a
Gray image with 1024 shades of gray between pure black and
pure white. Gray is the best choice of image if you wish to
scan a black and white photograph. With 10 bits of color
information per pixel, the disk space required to save a gray
image is eight times more than lineArt and 1/3 of that required
to save a 24-bit true color image.
Figure 4-7 Halftone Image
256 Colors
The 256 colors image provides 256 levels of color hues. The
disk space required to save an image in 256 colors is 1/3 of
that required to save a 24-bit true color image.
Figure 4-8 Halftone Image