Scanning for Different Media
FAQs | Glossary Of Terms | How-To Articles
The process and applications of a scanner are
relatively simplistic. It acts and functions much
like a copier. It has the same little scanning
bar that blinds you if you look into it, and instead
of feeding paper (though a rare few do) it transmits
the scanned object into your computer and allows
you to alter it digitally. In that respect, a
scanner can far surpass the average office copier.
Color Scanning
Scanning color pictures can be fun, but it's
also very challenging. You may expect to get the
same quality and detail as the original, but that's
not always the case.
A critical part of any scan is determining the
proper resolution, or dpi (dots per inch) setting.
Most scanning software allows you to select from
a range of settings, usually between 75-6000 dpi.
Of course, individual settings depend on the quality
of the scanner you're using, and technological
possibilities are expanding all the time.
Generally speaking, the greater the dpi (or
higher the resolution), means a better quality
scan. It also means that you've created a larger
file. A typical 400 dpi color scan can be as large
as two megabytes, whereas a 100 dpi black and
white scan is somewhere between 50-100 kilobytes.
There is also a major difference in the smoothness
of color shading. The edges of the scanned picture
become more jagged and irregular when using a
lower resolution setting.
The advantage to scanning in pictures at a lower
resolution is that the files are not as large,
and can be easily attached to an e-mail or saved
to a floppy disk. A 400 dpi file takes a long
time to transfer on a slower machine, and is too
large to fit on only a single disk. The disadvantage,
however, is that the lower resolution creates
a lower quality picture. Photo images found on
the Web are usually scanned at 72 dpi. While they
look great on your screen, these photos will not
print on a color printer very clearly.
Black & White Scanning
In scanning black and white text or photocopies,
the concern over resolution is not as great. Whether
it's photos or text, contrast is just as important
as resolution. Sometimes you'll need to darken
the black or grays to add contrast against a white
background. Adjusting contrast can cause otherwise
unnoticeable scratches or particles to appear.
Using Photoshop, you can easily increase or decrease
contrast once a scan is completed.
Another thing to be aware of is the quality
of the original you are scanning. The scanned
picture can never be better than it's original,
and you must keep in mind that there are always
minor deficiencies, scratches, or other imperfections
that will be enhanced by the scan. Keeping the
glass on your scanner clean, and double-checking
for wrinkles, smears and other debris on the original
will usually lead to a high-quality scan.
In scanning different kinds of media, the best
thing to do is experiment. Once you have some
of the basic principles down, you'll start to
see more and more ways to apply them, and even
begin to think of new things you might want to
try. Play around with scanning objects other than
pictures or documents. Most mid-range scanners
can capture almost anything that will fit on the
glass. Just keep trying different things and don't
get discouraged if success is slow to come. Proper
scanning techniques can take years to refine.
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