How To Use A
Scanner
by Sandy
Berger
The
scanner is a wonderful piece of equipment that allows us to copy documents,
photos, images, and other items for use in our computer. It works much like a
copy machine, but instead of creating an image on a piece of paper, the scanner
creates a digital image that can be displayed on a computer screen, manipulated,
e-mailed, and/or printed.
Flatbed
or Sheetfed
The two
main types of scanners are the flatbed scanner and the sheetfed scanner. The
flatbed scanner has a lid that opens to reveal a glass platen where the item to
be scanned is placed. Most flatbed scanners can scan paper documents, books,
photographs, and other flat objects such as leaves or pieces of fabric. Some
flatbed scanners can accommodate photographic slides with the addition of a
slide attachment. A sheetfed scanner differs in that it has a slot where a sheet
of paper can be fed into the scanner. A sheetfed scanner can accommodate only
flat pieces of paper such as paper documents, newspaper and magazine clippings,
and photographs. While the scanner itself is a piece of hardware, it is
accompanied by software that allows the hardware to communicate with the
computer.
Operating Instructions
The most
popular scanner today is the flatbed scanner. There are many manufacturers that
create flatbed scanners, and there are also many companies that develop scanner
software. This means the computer world has to accommodate an ever-increasing
number of combinations of scanners and software. Instructions on using scanners
are very hardware/software specific due to the many different manufacturers
involved. I will try to give you information that explains the concept of
scanning so that you can apply it to your own brand of scanner.
Some
scanners operate automatically. Once you have placed the document or article to
be scanned on (or in) the scanner, the scanner engages, and the software starts.
Other scanners begin the scanning process only when the Start or Scan button is
pressed. In other cases, the computer user must initiate the scan through the
software. This means clicking on the scanner software icon on the desktop or
clicking on Start, then Programs, then clicking on the icon that starts the
scanner application. Once the software is running, the scan can usually be
initiated by clicking on a scan icon. In the absence of such an icon, try
choosing File from the menu at the top of the screen. Once in the File menu, the
most common choice to start the scan is the menu choice Acquire. (In some
software, you will choose File, then Scanner or File, then Import). If you don't
see any of these options, check the manual that came with the scanner or try the
menu choice that seems most fitting.
Previewing
Once the
scan window is showing, most scanners give you the option of previewing the item
to be scanned before the actual scan occurs. The preview is a quick scan of the
image that will show you the position of the object to be scanned on the glass
platen. The area to be scanned will be shown by a dotted line. Look at the
preview and rotate or reposition the object on the glass, if necessary. You can
also use your mouse to move the dotted line (click your mouse on the line and
drag it) to resize or change the perimeter of the scan. Just click your mouse on
the line and drag it to reposition it to scan more or less of the object. Use
the dotted line to encompass only the area that you want to scan.
Resolution
Before
initiating the scan, you will also want to set the scanning resolution.
Resolution is measured in dpi (dots per inch). Try using a dpi between 100 and
200 to start. The higher the resolution or dpi, the more detailed the image.
However, the higher the resolution, the larger the file, and the more room it
will take up on your hard drive. Images scanned at a very high resolution can be
massive; so don't use a higher resolution than you need.
Think
about how you will use the image before you set the scan resolution. You don't
need a high resolution for images that will only be seen on a low-resolution
device like a computer screen. 100 dpi might be adequate for viewing on the
computer. However, you probably won't be happy with a 100 dpi resolution when
the image is printed on a high-resolution ink jet printer. Try 200 dpi or higher
for images that you will print.
Types
of Scans
Other
decisions to be made when you are scanning regard the type of scan. Some
scanners have preset options that are easy to recognize. Other scanners use more
obscure choices like: Color (sometimes referred to as Millions of Colors), Gray
Scale, Line Art, and/or Halftones. If you are faced with these choices, use
Color or Millions of Colors for photographs and color images. Use Gray Scale for
black and white photos and charcoal drawings. Use Line Art for non-color printed
text. Halftone images often appear in magazines and newspapers, but are not
ordinarily used otherwise. They do not work well for images to be shown on a
screen.
To scan in
black text, use a pre-chosen setting for that, if your scanner has one. If not,
use Line Art or Black and White at 300 dpi.
TWAIN &
OCR
Here are a
few other terms you should know when scanning.
TWAIN:This
is the industry standard used to obtain scan information and transfer that
information between scanner and computer. Nearly every scanner made today is
TWAIN compatible. If you are curious about what TWAIN stands for, it is known
in computer circles as the Technology Without An Interesting Name, but others
in the know say it doesn't stand for anything.
OCR:
A scanner simply takes a picture of the text on a page. In order to use a word
processing program to work with text that you have scanned, you need to
convert the picture of the text into a format that will be understood by a
word processing program. An OCR (Optical Character Recognition) program will
make the necessary conversion. Most scanners come with at least the lite
version of an OCR program. If you will be scanning in a lot of text, you may
want to upgrade to the full version.
Don't be
afraid to play with the various scan settings. If you don't like the results of
a scan, discard it and try again. Experiment with the various settings to see
the difference, and you'll be learning about your scanner while having a little
fun as well.
by-http://www.aarp.org
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