Scanning Overview
The power of scanning and the opportunity for placement of scanning technology
into a customer's environment is endless. Advances in scanner technology, archiving,
and retrieval software make it possible to virtually eliminate the paper generated
and repeatedly handled in today's business processes. Sharp offers systems and
software in conjunction with our Authorized Dealers to enable your business to
take advantage of this revolutionary, yet easy-to-use, technology.
The advent of the Sharp Network Scanner available on our MFP and Document Communication
System product lines allow for the rapid integration of hard copy documents into
a system where they can be accessed on demand. This eliminates the need to copy
documents and forward them internally or to outside constituents, and it makes
for easy retrieval if the document is needed in the future.
What Is a Network Scanner?
Many people are familiar with desktop scanners. A scanner converts pictures,
graphics, drawings, photographs or text into digital characters for transfer to
a computer. The transferred object can then be edited in diverse ways with the
aid of image editing software, or "read" with the aid of text recognition software
(OCR).
The primary task of a scanner is to digitize a two-dimensional document, e.g.
a sheet of paper or a page of book. Digitization involves creating an image of
the original document based on digital data. A Network Scanner works the same
way as a desktop scanner, except that it transmits a scanned image over a network
to a designated file directory or e-mail address.
How a Scanner Works
The most important part of the scanner is the CCD (Charge Couple Device) unit.
The CCD, in short, is the "eye" of the scanner.
The following are steps that take place when a scanner performs its intended
operation:
- The document is placed on the glass platen or in the auto-document feeder and
the scanning process begins (either via hardware by pressing a scan button or
by software prompt)
- A lamp is used to illuminate the document on the platen
- The scan head (i.e the lamp and the CCD) moves across the document to make a
pass
- The light from the lamp hits the document and reflects. It then goes via a set
of mirrors to the CCD array
- The captured image is sent to the computer
Resolution
Scanning resolution determines the quality and readability of the scanned document.
The resolution is defined as the number of digital dots per inch captured by the
scanner. Scanners can extend this resolution with interpolation, a mathematical
process which produces more dots per inch, but the basic optical resolution is
the important number. Modern consumer scanners have optical resolutions in the
range of 600 dpi to 1600 dpi.
Optical Character Recognition (OCR)
Optical Character Recognition is the process of turning a picture of words (such
as a scan of a typed document) into an editable document you can open and use
in desktop publishing software, word processor, or other text editor.
Tips for Better OCR Results
Whatever type of program you use (and no matter what accuracy rate the program
claims) there are things you can do to help ensure the best possible results from
your OCR software:
- Start with a good original: Wrinkled or smudged originals tend to affect OCR accuracy
- Make the scan the best you can: Make sure the scanner bed is clean and smudge-free. Keep the document straight
and even so you don't get a "skewed" image. Adjust the color/contrast/brightness
so the background is light/white and free of "artifacts" (such as a pattern in
the paper) and the text is dark. Scan at 300 dpi or better
- Turn one document into many: With older or stripped-down software, graphics, lines on forms, columns of text,
and other formatting may cause problems. Try breaking the scanned original down
into smaller chunks (crop out non-text elements or save columns of text as individual
images) and run your OCR software on each part separately. You'll lose formatting
but gain a more accurate text document
- Try different settings: Experiment with different options in your software. If your first attempt is
less than usable, adjust the controls
- Proofread: No matter how accurate the program, all are fallible. Proofread the finished
document
Included Software
Most scanners come with basic image editing software and software which converts
a printed page into a typed document for your word processor. Sharp includes Sharpdesk®
software for this purpose. Sharpdesk software allows you to OCR, annotate, edit,
email and file scanned files.
Features to Consider
When buying a scanner, take into account the many available features. Here's
what you should consider:
- Optical resolution: Resolution is a measurement in dots per inch (dpi) of the sharpness and clarity
of an image. A scanner with 300-dpi resolution can capture an image with 90,000
dots per square inch. In general, 300 dpi is adequate for scanning. But if you
plan to print what you scan, look for a scanner with a higher dpi, such as 600
or 1200
- Sheet-feeder: Scanners with auto document feeders (or sheet feeders) are excellent to scan
multiple pages for document management (like invoices or receipts) or edit in
a word processor, then a sheet-fed scanner should be your first choice. A sheet-feeder
is also required to scan documents longer that 8.5" x 14" (legal) sized documents
- Bit depth: This refers to the number of bits used to capture each dot. The higher the number,
the more color gradations will be visible. A 24-bit scanner will be suitable for
scanning photos, drawings, and texts, while a 30- or 36-bit scanner is best for
scanning film or transparencies.
- Speed: If you plan on using a network scanner to scan tens to hundreds of pages at
a time, speed is a major consideration.
- Ease of use: This feature is more important than numbers. After all, it doesn't matter how
high the resolution is if you can't figure out how to use it. Features such as
one-step buttons (which allow you to complete routine tasks in one step) and user-friendly
software greatly contribute to ease of use.
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