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8-bit grayscale: Images that contain 256 possible shades
of gray.
24-bit color: 24-bit color images are composed of (3) 8-bit
color channels. Each color channel, similar to an 8-bit grayscale image, contains
up to 256 colors. When combined, the red, green and blue channels provide up
to 16.7 million colors. 24-bit color is also known as True Color and Photo-realistic
Color.
32-bit color: 32-bit color images have 4 color channels of
8 bits each - one channel each for red, green and blue, plus 8 bits of grayscale
data to provide higher detail.
Bitonal: An image or file comprised of pixel or dot values
of either black or white.
Grayscale: (1) An image type consisting of shades of gray,
with no color. The standard grayscale image contains 8 bits per pixel, which
allows for 256 shades. (2) The depiction of gray tones between black and white.
A grayscale monitor is able to display distinct gray pixels as well as black
and white ones, but not color pixels. (3) An orderly variable progression in
definite steps of gray densities ranging from minimum zero (white) to maximum
density (black). A strip of standard gray tones placed at the side of the original
copy during a photography to measure tonal range obtained. Used in processing
film or materials such as photographic paper and plates.
Halftone: A simulation of continuous tones by the use of
black or overlapping process color dots of varying size or position.
Pixel: The basic building block of all images -- a simple
dot. In bitonal images, it is merely a black or white dot (see "Bitonal"
definition above). In gray scale images, dots will have between 1-to-256 possible
values of gray (for an 8-bit gray scale image).
Resolution: Indicates the number of dots, often measured
in dpi, that make u an image on a screen or printer. The larger the number of
dots, and thus the higher resolution, the finer and smoother images can appear
when displayed at a given size. Low resolution caused jagged characters. The
ideal resolution is a trade-off between quality and the overhead in storage
power and processing strength required to use it.
Hardware and Interfaces
ADF: Automatic Document Feeder. A device that holds pages
and feeds them one after another into a scanner.
CCD: A charge-coupled device, or CCD, is a light sensitive
electronic device that converts light into an electrical charge.
FB: Flatbed. A scanner design in which the document is placed
in the scanner's bed, either manually or by an automatic document feeder, and
remains stationary during scanning. As a result, flatbed scanners provide a
more stable target than other scanner designs, but they are generally slower.
Data rate: The speed of a data communications channel, measured
in bits per second.
Hz: Abbreviation for Hertz; cycles per second. Often used
with metric prefixes, as in kiloHertz (kHz).
Interface: 1. Mechanical or electrical link connecting two
or more pieces of equipment together. 2.A point of demarcation between two devices
where the electrical signals, connectors, timing and handshaking are defined.
TWAIN and ISIS: TWAIN and ISIS are industry standard scanner
drivers. They allow you to seamlessly connect your scanner to hundreds of scanning
applications.
Image compression boards: An imaging-dedicated processor(s).
Relieves the CPU (Central Processor Unit-the computer's main chip) from many
imaging-specific tasks - compression, decompression, display, zooming, shrinking,
scale-to-gray. In fact, does them better than the CPU.
SCSI: Small Computer System Interface. Pronounced "scuzzy".
An Industrial standard (of sorts) for connecting peripheral devices and their
controllers to a microprocessor. SCSI defines both hardware and software standards
for communication between a host computer and a peripheral. Computers and peripheral
devices designed to meet SCSI specifications should work together.
USB: USB, or Universal Serial Bus is a standard computer
interface that is included with the majority of personal computers. The USB
interface allows the user to connect external devices including scanners, digital
cameras, printers, keyboards and mice to the PC. The current USB specification
is 2.0. The 2.0 standard supports and is backwards compatible with the previous
specification, 1.1. For more information to to http://www.usb.org.
Business Process
Batch Scanning: Sequential scanning of multiple originals
using previously-defined, unique settings for each.
Long Document Scanning: Long document scanning functionality
is used to process longer than normal paper sizes. Long documents can be in
the form of loan documents, medical equipment logs, and similar documents.
Double Feed: The feeding of two sheets of paper at once.
Sometimes on roller based scanners this can occur so cleanly that it cannot
be detected.
Image Enhancement / Image Processing
Color Dropout: Color dropout is a feature that is used to
ignore specific colored ink(s) from preprinted forms/documents during the scanning
process. This can be used to remove colored backgrounds or colored text templates
in the scanned image. Depending on the model, Fujitsu scanners are capable of
dropping out colors in the red, green or blue color spectrum.
Color Correction: The process of adjusting an image to compensate
for scanner deficiencies or for the characteristics of the output device.
OCR / ICR / OMR: OCR or Optical Character Recognition is
a software process where an image is converted to text data. Once the image
is converted, the text can be edited by a word processing application or the
text data can be used as an index to perform full text searches and retrieval
based on the text content of the document
Scanner Settings
DPI: Dots per inch. A measurement of scanner resolution.
The number of pixels a scanner can physically distinguish in each vertical and
horizontal inch of an original image. Business documents are normally scanned
at a resolution between 200 dpi and 400 dpi.
Simplex: A document scanner that copies single-sided documents.
Duplex: The ability of a scanner to scan both sides of a
sheet simultaneously. Requires two scanner cameras and often two processing
boards.
Portrait Orientation: An image registered so that is is taller
than it is wide, with the narrow edge running along top and bottom. When scanning,
orientation is determined b the leading edge of the document.
PPM: Pages per minute. A measurement of the throughput speed
of a scanner - how many letter-size pages the scanner can scan in one minute.
Beware: ppm can be misleading.
Throughput: The actual amount of useful and non-redundant
information which is transmitted or processed. The relationship of what when
in one end and what came out the other is a measure of the efficiency of that
communications link - a function of cleanliness, speed, etc.
Transport speed: The speed at which the mechanical transport
runs, measured in inches/centimeters per second (ips/cps).
General Terms
VAR/VAD: Value Added Reseller. VARs buy equipment from computer
manufacturers, add some of their own software and possibly some peripheral hardware
to it, then resell the system, with its newly added "value" to end
users.
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