16 A-61195 July 2003
Image Type Select the mode you want to use for your scans on the Image Type drop-
down menu.
Black and White—the image appears in black and white with no intermedia te
shades of gray. That means that each pixel of the image is either 100% black
or 100% white.
Choose Black and White if you are scanning text or pen and ink drawings.
Since only one bit of black or white information is required p er pixel, the
file size of a Black and White image is on ly about 1/24 the size of a 24-Bit
Color image.
Halftone—a halftone is a picture like that which is usually seen in a
newspaper or magazine. Since a halftone is a type of black-and-whi te
image, the file size of a halftone imag e is only about 1/24 the size of a 24-Bit
Color image.
Halftone simulates grayscale by using varying dot sizes. If you vi ew a halftone
image at a certain distance, it looks much like a grayscale i mage, but the file
size is smaller.
When you select Halftone, a submenu appears that allows you to s elect a
halftone pattern.
8-Bit Gray—a single-channel image consists of at least 256 shad es of gray.
An 8-bit scanner produces a grayscale image with 1024 shade s of gray
between pure black and pure white. Choose this option if you ar e scanning
black-and-white photographs.
With 8 bits of color information per pixel, th e file size of an image is eight times
larger than a Black and White image and 1/3 the size of a 24-Bit Color image.
8-Bit Color—an 8-Bit Color image provides 256 color hues in the image.
The file size of a 256 color image is 1 /3 the size of a 24-Bit Color image
(TWAIN only).
24-Bit Color—a 24-Bit Color image consists of three 8-bit color channe ls. The
red, green, and blue channels are mixed together to create a com bination of
one billion colors which give a more true-to-life quality t o the image. Choose
24-Bit Color if you are scanning color photos.