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This
section is designed to help you learn what you need to know before
scanning.
Before
we go on, please have a look of the Digital
Imaging, a very brief explanation of "what is an image anyway?"
or view the Scanner Basic, which explains
the basic mechanism of a flatbed scanner.
You
don't need a degree in optics to use a scanner. It just seems that
way. Here are the basics you should keep in mind, courtesy of the
scanning experts at FamilyPC.
Basically,
scanning at a higher resolution captures more details of the photo,
resulting in a sharper image and a bigger file. A good rule of thumb
is to scan for print projects at no lower than 150 dots per inch;
for projects where the image is going to be shown on-screen, a minimum
of 72 dpi should be fine. Remember, if you plan on printing an image
on a 360-dpi printer, don't Sean it at a higher resolution.
A
good rule of thumb for uncompressed file size: A true-color (24-bit)
scan of a 3-by-5inch color photo at 600 dpi will be about 16 MB;
the same image at 200 dpi will be roughly 1.8 MB. If you're going
to be scanning a ton of images, you can probably use an affordable
removable-storage device like Iomega's Zip drive. Most scanning
software comes with a compression option; use it--it may compress
your image to roughly one-tenth its original size (though it's more
likely to compress to only one-third the original size).
While
image-file types are becoming more standard, there are still several
options for saving your scanned images -- for example, PCX and BMP
for Windows, TIFF and PICT for the Mac and GIF and JPEG for both.
If you're planning to import an image into another program, be sure
the file type matches up.
For
more information on image file type, click here.
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