Document Scanner Glossary
By +Dax Radder
A glossary presents precise and short definitions of terms, concepts or acronyms. They aim at helping the end user who is unfamiliar with the exact definition of a term. Thus, it’s always nice to know what the technological terms mean when comparing scanner to scanner.
Here is a list of the most commonly used document scanner terms and their respective definitions:
ADF - Automatic Document Feeder. A device that holds pages and feeds them one after another into a scanner.¹
Adobe® Acrobat® - Software that allows users of different computer systems (PC, Macintosh, minicomputer, mainframe) to transfer a document from one computer to another (via disk or Internet), without any change in how the document looks on the screen or in print. Acrobat preserves colors, fonts, graphic elements, and layout of a document and reproduces them accurately. It converts the document’s file format into portable document file (PDF) format which can be read by any computer by using AcrobatReader software (without needing the application program with which the document was originally created). PDF is the de facto worldwide standard for platform-independent distribution of books, brochures, catalogs, ezines, newsletters, and other types of literature.
ABBYY Fine Reader OCR - Optical Character Recognition software (see OCR below).
Alpha Channel – An 8-bit channel reserved by some image-processing applications for masking or additional color information.¹
Bitonal - An image or file comprised of pixel or dot values of either black or white.¹
8-bit grayscale – Images that contain 256 possible shades of gray.¹
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.¹
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.¹
Cardiris™- Business card scanning software. Cardiris™ quickly scans your paper business cards, captures the information they contain and instantaneously creates electronic contacts to be sent to your favorite contact manager, such as Outlook, etc.
Cardminder™ – A proprietary business card scanning software owned by Fujitsu (PFU Ltd.)
CCD - A charge-coupled device, or CCD, is a light sensitive electronic device that converts light into an electrical charge.¹
CIS - Contact Image Sensor, abbreviated as CIS, a type of optical flatbed scanner that does not use the traditional CCD arrays that rely on a system of mirrors and lenses to project the scanned image onto the arrays. CIS scanners gather light from red, green and blue LEDs(which combine to provide white light) and direct the light at the original document being scanned. The light that is reflected from the original is gathered by a lens and directed at an image sensor array that rests just under the document being scanned. The sensor then records the images according to the intensity of light that hits the sensor.³
A CIS scanner is more compact than a CCD scanner and can be used in smaller products than CCD scanning technologies. CIS scanners also require less power than CCD scanners and often can run off battery power or the power from a USB port. CCD scanners, however, provide higher-resolution scans. ³
Color Correction - The process of adjusting an image to compensate for scanner deficiencies or for the characteristics of the output device.¹
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.¹
CPU - Pronounced as separate letters it is the abbreviation for central processing unit. The CPU is the brains of the computer. Sometimes referred to simply as the central processor, but more commonly called processor, the CPU is where most calculations take place. In terms of computing power, the CPU is the most important element of a computer system.³
Daily Duty Cycle or Duty Cycle - Inprint and copy terminology, duty cycle refers to the number of copies or prints that the device can reliably produce on a monthly basis. Exceeding the duty cycle number on a regular basis can lead to equipment malfunctions and breakdowns over time. Alternatively, not printing or copying in numbers close to the duty cycle could mean you have over-purchased on equipment.³
Data rate - The speed of a data communications channel, measured in bits per second.¹
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. Documents are normally scanned at a resolution between 200 dpi and 400 dpi.¹
Driver - A program that controls a device. Every device, whether it be a printer, disk drive, or keyboard, must have a driver program. Many drivers, such as the keyboard driver, come with the operating system. For other devices, you may need to load a new driver when you connect the device to your computer. In DOS systems, drivers are files with a.SYS extension. In Windows environments, drivers often have a.DRV extension.
A driver acts like a translator between the device and programs that use the device. Each device has its own set of specialized commands that only its driver knows. In contrast, most programs access devices by using generic commands. The driver, therefore, accepts generic commands from a program and then translates them into specialized commands for the device.³
Duplex Scanning - The ability of a scanner to scan both sides of a sheet simultaneously. Requires two scanner cameras and often two processing boards.¹
DVD-ROM - A new type of read-only compact disc that can hold a minimum of 4.7GB (gigabytes), enough for a full-length movie.
The DVD-ROM specification supports disks with capacities of from 4.7GB to 17GB and access rates of 600 KBps to 1.3 MBps. One of the best features of DVD-ROM drives is that they are backward-compatible with CD-ROMs. This means that DVD-ROM players can play old CD-ROMs, CD-I disks, and video CDs, as well as new DVD-ROMs. Newer DVD players can also read CD-R disks.
DVD-ROMs use MPEG-2 to compress video data.³
Energy Star - is a government-backed program helping businesses and individuals protect the environment through superior energy efficiency.
Evernote - A digital, online notebook application that allows the user to jam all of his/her notes, videos, web clippings, snapshots into one area, archives it and then allows all that information (notes) to be found later through searchable text. Another quaint definition from Cesar at pmforthemasses.com is “Evernote is supposed to be a place where you put things you want to remember but don’t want or can’t keep it in your brain.”
grayscale - 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.¹
Halftone - A simulation of continuous tones by the use of black or overlapping process color dots of varying size or position.¹
Host - computer in which an applications or database resides.¹
Hz - Abbreviation for Hertz; cycles per second. Often used with metric prefixes, as in kiloHertz (kHz).¹
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.¹
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.¹
ISIS™ - Image and Scanner Interface Specification (ISIS) is an industry standard interface for image scanning technologies, developed by Pixel Translations in 1990 (today: EMC captiva). ISIS is a well-established standard interface for capturing office documents using small format scanners in EDM (electronic document management) applications. ²
LCD - Short for liquid crystal display, a type of display used in digital watches and many portable computers. LCD displays utilize two sheets of polarizing material with a liquid crystal solution between them. An electric current passed through the liquid causes the crystals to align so that light cannot pass through them. Each crystal, therefore, is like a shutter, either allowing light to pass through or blocking the light. ³
LED – Abbreviation of light emitting diode, an electronic device that lights up when electricity is passed through it. LEDs are usually red. They are good for displaying images because they can be relatively small, and they do not burn out. However, they require more power than LCDs.³
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.¹
Mean Time Between Failure – A statistical measure of reliability, this is calculated to indicate the anticipated average time between failures of a device. The longer the better.¹
Memory Capacity – The maximum or minimum amount of memory a computer or hardware device is capable of having or the required amount of memory required for a program to run.
Monochrome – One color. Monitors, for example, can be monochrome, grayscale or color. Monochrome monitors actually use two colors, one for the display image (the foreground) and one for the background. Graphic images can also be monochrome, grayscale, or color. ³
Multi-Feed Detection – “Multi-feed” is a feeding error that occurs when two or more sheets in the ADF paper chute are fed simultaneously into the scanner. If the “multi-feed” is not detected, important information may be not be scanned. With multi-feed detection, the scanner indicates a message and ceases the scanning to prevent such an error from occurring.
OCR - Often abbreviated OCR, optical character recognition refers to the branch of computer science that involves reading text from paper and translating the images into a form that the computer can manipulate (for example, into ASCII codes). An OCR system enables you to take a book or a magazine article, feed it directly into an electronic computer file, and then edit the file using a word processor.
All OCR systems include an optical scanner for reading text, and sophisticated software for analyzing images. Most OCR systems use a combination of hardware (specialized circuitboards) and software to recognize characters, although some inexpensive systems do it entirely through software. Advanced OCR systems can read text in large variety of fonts, but they still have difficulty with handwritten text.
The potential of OCR systems is enormous because they enable users to harness the power of computers to access printed documents. OCR is already being used widely in the legal profession, where searches that once required hours or days can now be accomplished in a few seconds.³
Paper Sizes - For example: A4, A5, A6, B5, B6, business card, post card, letter, legal or custom size. Many paper size standards conventions have existed at different times and in different countries. Today there is one widespread international ISO standard (including A4, B3, C4, etc.) and a localised standard used in North America (including letter, legal, ledger, etc.). The paper sizes affect writing paper, stationery, cards, and some printed documents. The standards also have related sizes for envelopes.²
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).¹
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.¹
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.¹
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.¹
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.¹
Simplex Scanning – A document scanner that copies single-sided documents.
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.¹
Transport speed – The speed at which the mechanical transport runs, measured in inches/centimeters per second (ips/cps).¹
TWAIN – TWAIN and ISIS are industry standard scanner drivers. They allow you to seamlessly connect your scanner to hundreds of scanning applications.
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.¹
VAR/VAD - Value Added Reseller/Dealer. 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. A VAD is similar, but is generally less directly in touch with the end user.¹
Video Scanner Interface Board - An add-in board residing in the host computer which enables communications and control of the scanner device. The board provides device control and file or data compression. Also known as an accelerator or compression board.¹
The definitions in this glossary were prepared, in part, from Moore’s Imaging Dictionary, published by Flatiron Publishing, Inc. Also, from Wikipedia, Webopedia and other fine sources.
¹ From Moore’s Imaging Dictionary
² From Wikipedia
³ From Webopedia
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