How to Scan
The basic operation of your scanner, regardless of its make or model, can
probably be summarized in three easy steps.
·
One,
place the original on the scanner.
·
Two,
open your scanning software and tell it to make the scan, usually by clicking
either File > Scan or File > Acquire (or, even more simply, push the
"Scan" button on the device itself).
·
Three,
save the resulting image to your computer, so later you can print it, e-mail
it, or post it to the Web.
Getting the best scans, however, is not always so simple. Here are
some ways in which you can guarantee you get the best possible results from
your scanner.
Resolution,
bit-depth, and file format:
Before you start to scan, think about how you plan to use the final
image. Is it going to be used in printed material? Will you perhaps
print it out using your own photo-quality printer? Or is the image
intended for on-screen viewing only, perhaps posted to a website or e-mailed to
a friend or family member? Depending on the final product, you will want
to set your scanner to capture the optimal image in terms of file size and
picture quality. There are three basic settings you can adjust in order
to do this.
- Resolution
Digital images are broken down and stored as pixels, dots of lights
with their color value stored as a series of zeroes and ones.
Resolution measures the number of pixels-per-inch (ppi),
and thus serves as a guideline for the amount of detail available in the
final image. Most scanners are capable of capturing an image in a grid
pattern, 300 ppi wide by 300 ppi
deep. This gives you a very high-quality, detailed image. But
most image output devices (printers and monitors) are not capable of
utilizing such fine detail. Average monitors, for example, only
display at a resolution in the range of 72 to 96 ppi.
Making a high-resolution scan of an image that will only appear on screen
will result in an unnecessarily large file size. However, if you are
planning on printing your image on a high quality printer, you will not be
satisfied with the outcome if you made your scan with a lower
resolution.
- Bit-depth
Bit-depth refers to the number of colors that the scanner will
capture. A 1-bit scan will capture only black and white, a 4-bit
scan will capture 16 colors, and an 8-bit scan will capture 256
colors. With a 16-bit scan you will get over 65,000 colors, while a
24-bit scanner will capture 16.8 million colors. The higher the bit
depth, the better the color, but only at the expense of file-size.
For online viewing, an 8-bit scan will be more than sufficient, but for
color printing bump the scan up to the highest bit-depth available for
your
scanner.
- File format
The format in which you save your scanned image
will be the final crucial choice you have to make. The two most
common formats for image files are TIFF and JPEG.
- TIFF uses a lossless
compression process, which means that you'll have no loss of detail in the
image. You should use the TIFF format when you plan to print your
image.
- JPEG, on the other hand,
should be used if you are going to put your image on the Web or send it
via e-mail. While some detail is lost in the compression process, it
won't be noticeable when viewed on screen, and it provides a compact file
size for speedy downloading.
Best scan tips
- Choose the best photo.
While you can punch up color and fix some fuzziness with image editing
programs, the better your original image, the better your final scan will
be. Choose pictures that have good lighting and contrast to get the
best
results.
- Scan your photo in the
orientation in which the image will be used. Some detail is lost
when you rotate the image in your desktop publishing or image-editing
program.
- Scan only what you
need. Don't scan a whole image if all you need is a small
portion. Your scanner software has tools to preview and select only
the portion of the original that you
want.
- Use your image editor, not
your scanner software, to make adjustments to color and sharpness of your
scanned
image.
- Know your scanner
software. If a manual is available, read it from cover to cover to
know how to get the most from your particular software. Otherwise,
spend time playing with the program until you get the hang of
it.
- Practice, practice,
practice. The more scans you make, the better you will understand
how to get the best images from your scanner