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A
scanner captures images from photographic prints,
posters, magazine pages, and similar sources for
computer editing and display. Scanners come in
hand-held, sheet feed, flatbed and can be integrated
with printers. Most
scanner can see more colors than the printer can
print, higher than 24-bit or 16,777,216 colors.
Resolution ratings are measured by hardware and
software. The average optic resolution of scanners
are 300x600 dpi, 600x600 or 600x1200, but these
resolutions can be enhanced by thousands of dot per
inch through software. Scanners attach to your
personal computer through a Universal Serial Bus (USB), the
printer port or
with a Small Computer System Interface (SCSI).
Scanners usually come with software and can be used
within applications through a TWAIN program.
TWAIN
is a program that lets you scan an image, using a
scanner, directly into the application where you
want to work with the image. Without TWAIN, you
would have to close an application that was open,
open a special application to receive the image, and
then copy the image to the application where you
wanted to work with it. The TWAIN driver runs
between an application and the scanner hardware.
TWAIN usually comes as part of the software package
you get when you buy a scanner. It is integrated
into graphic software and most word processors,
among others, as a 'scan image' or 'insert image'
menu type. |
