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Scanners are being added to home computers at a very rapid rate as their
price goes down and their performance improves. Most genealogists are
involved in sharing and caring for the past and have many uses for a scanner.
Here are a few tips and tricks.
1. Think about file size
One thing you will learn quickly about scanned images is that they can
take up a LOT of room on your hard drive. A fairly ordinary picture can
take up 1.5 megabytes of disk space which is equivalent to about 180,000
words (a decent-sized novel). The old adage that "a picture is worth 1,000
words" is more than true with scanned images!
Most scanners for the home market now have a resolution of 600dpi (a
general rule is to ignore all resolution specifications given for the
scanners except the lowest). A 6" x 4" photo print scanned at
600dpi produces a 25 megabyte image! Scanning a small portion of a photo
for later enlargement is one of the few occasions that you will need the
highest resolution.
In a world of unlimited disk space, we would scan everything at the maximum
possible resolution and save it at 100 percent of the original size. In
the real world we need to be more practical. Learn to vary your scanning
depending on the nature of the picture: if the subject is important to
you, by all means devote the space you need. On the other hand you can
save lots of file space by scanning only that portion of the image you
need and/or saving as a smaller size.
2. Compressing images
When we received the images for our "Dating Old Photos" feature (Family
Chronicle May/June 1998), few people seemed to be aware of image compression,
yet this is simple. All images can be saved as JPEGs (said JAY-Pegs) which
take up a fraction of the original file size. When you open up a JPEG
image, it is automatically decompressed and displayed as normal. Some
some programs give you no choice as to how far the image can be compressed
while others allow you to make fine gradations.
You can't scan an image as a JPEG the image will almost always
be a TIFF file. However, instead of just naming the image before you save,
go to Save As, scroll down to JPEG and then Save.
At this stage you may be offered a degree of compression, usually on
a scale of 1-10 (1 is most compressed, 10 the least). Experiment to find
the right degree for you. At the low (1-2) end, images lose a bit in quality.
Until you are familiar with this feature, you may wish to try an 8.
JPEG files are considerably smaller than TIFF files savings of
95 percent are common. JPEG compression should not be used on any file
that is to be opened, modified and resaved; something that you are likely
to do when restoring damaged or faded photographs. This is because while
the quality loss using JPEG is minimal, the problems compound themselves
at each saving of the file.
The picture on the left is derived from a TIFF file. On the right it
is shown as a JPEG image. There is no discernible quality loss.
3. Cut up text prior to using OCR
Almost all scanners come with Optical Character Recognition (OCR) software
but this is usually a "lite" or stripped version of a full package that
the software publisher wants to sell you. Although these packages lack
some of the sophistication of full-fledged OCR programs, they are far
simpler to use.
Simpler programs sometimes have problems with multiple columns of text
or documents that include photos, logos, etc. There's an easy solution:
photocopy the original and cut the columns into strips and remove the
photographs.
Many people drop OCR as their first attempts are disappointing. If you
have only limited need for OCR, don't bother to pursue this but if you
have a need it really is worth using. Some scanners have a setting that
allows you to scan for OCR: this will not always produce the best results
- you can scan using Grayscale or Line Art settings.
There's also a common rumor that scanning an enlarged photocopied version
improves OCR accuracy. This is a myth unless your scanner's resolution
is below 300 dpi.
4. Manipulate AFTER scanning usually
You usually have some control over the color, contrast, etc. while scanning
avoid using this. After scanning, the image is transferred automatically
to the image manipulation program where you are offered much the same
(but more involved) control over your image. The order should be: 1. Scan
a basic image, 2. Save it, 3. Play with it.
Don't correct the image when scanning; do your manipulation in the main
program. Two exceptions are when scanning as line-art or using descreening.
Old engravings, and even text saved as an image, are best scanned as line
art at 600 dpi (or twice the resolution of the output device) using the
interpolation feature (which is automatic). These images are saved as
bitmaps and, once scanned, can hardly be manipulated.
5. Descreen
Images in newspapers and magazines are reproduced quite differently from
photographic prints. They are reduced to a series of small dots. When
scanning these you can easily get an interference pattern between the
dots on the original and the dots scanned. Some scanners allow you to
"descreen" when scanning: blurring the dot pattern so it appears more
like a photograph. This process is very effective and is far, far better
than trying to overcome the screen or patterning in your photo enhancement
software.
6. Learn to adjust contrast, brightness and sharpness
The idea of doing their own photo restoration scares many people. Certainly
retouching damaged photos requires a considerable degree of skill but
if the image is basically sound, you can improve it considerably by adjusting
the brightness, contrast and sharpness not unlike setting a good
TV picture. Most of the photo enhancement programs feature an automatic
facility (not always prominent in the manual). Try this it will
often (not always) improve your image, sometimes magically. If your changes
do not show any improvement or look worse, simply Undo those changes and
try again.
7. Save Black and White as Black and White
About 80 percent of the electronic images submitted for our "Dating Old
Photos" article were submitted as color images even though the originals
were almost all black and white. All you are doing here is to increase
your file sizes threefold and possibly saving the distortion of sepia
fading. There is no advantage at all in saving monochrome images as color.
8. What you see is not always what you get
Photographic images on a computer monitor can often look fabulous
but we are actually viewing them at low resolution, usually at 72 dpi
(the resolution also used on the web). Photographs in most magazines
including Family Chronicle are reproduced at 133 dpi and
many color printers are 720 dpi or more. Be aware of this. You need different
resolutions for different purposes.
9. Don't keep your images on your hard drive
Although computer hard disk space is now a fraction of the cost that
it was a few years ago, it is a lousy place to keep your precious images.
Just ask anyone who has been around computers for over a decade: you'll
be lucky to find someone who has not lost a hard drive at some time (the
author has lost hard drives four times in 15 years). The data can be recovered
by specialists but the costs are horrendous.
If you have a reasonable number of black and white images and you take
our recommendations to JPEG them, you can use 3-1/2 inch floppy disks.
They are cheap and almost all computers can read and write to these (well,
for the time being anyway).
Removable hard drives and other forms of mass storage offer a good solution
you can have as many 1 gigabyte backup disks as needed. These are
fine but the disks are not inexpensive.
A CD-R recordable CD drive may be your best bet. Although
they cost about 50 percent more than removable hard drives, the blank
disks cost only $1.00-$3.00 each and will hold 650 megabytes of data.
The author's entire (and extensive) photo archives all fit onto one CD.
The inability to re-record is actually a plus as you can never erase your
data in error.
10. Making Prints
It's all very well to scan and share your pictures electronically but
let's face it, most of the time we want a traditional print for many occasions.
Technology available to print out files at any decent quality has lagged
on the electronic side. "Photo realism" kits for ink jet printers have
been very disappointing at least until recently. Color laser printers
can produce excellent results but these are very expensive.
A new generation of color printers capable of producing almost-photographic
images on special paper have now appeared. The developments in this field
have been so dramatic that the whole picture (pun not intended) may have
changed by the time you read this. Many photographic stores and "quick
printers" now have facilities for producing quality output from your files.
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