scanner


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scanner

1. a device, usually electronic, used to measure or sample the distribution of some quantity or condition in a particular system, region, or area
2. any of various devices used in medical diagnosis to obtain an image of an internal organ or part
3. short for optical scanner

scanner

[′skan·ər]
(computer science)
A device that converts an image of something outside a computer, such as text, a drawing, or a photograph, into a digital image that it sends into the computer for display or further processing.
(communications)
That part of a facsimile transmitter which systematically translates the densities of the elemental areas of the subject copy into corresponding electric signals.
(engineering)
Any device that examines an area or region point by point in a continuous systematic manner, repeatedly sweeping across until the entire area or region is covered; for example, a flying-spot scanner.
A device that automatically samples, measures, or checks a number of quantities or conditions in sequence, as in process control.

scanner

(1)
An input device that takes in an optical image and digitises it into an electronic image represented as binary data. This can be used to create a computerised version of a photo or illustration.

A scanner may be linked to optical character recognition software allowing printed documents to be converted to electronic text without having to type them in at a keyboard.

scanner

(2)

scanner

(1) A synonym for antivirus program.

(2) A smartphone application that reads barcodes. See mobile tagging.

(3) An optical device that reads a printed page or transparency and converts it into a graphics image for the computer. The scanner does not recognize or differentiate in any manner the content of the material it is scanning. Everything is converted into a bitmapped image, which is a pattern of dots. See bitmapped graphics.

Optical Character Recognition (OCR)
Optical character recognition systems use scanners to capture printed text and convert it into computer-readable characters for editing. See OCR and document scanner.

Scanners and Cameras
Scanners are similar to digital cameras, except cameras can focus into infinity. Desktop scanners have physical dimensions that determine the size and bulk of the material that can be scanned. Automatic feeders are used to scan stacks of paper, typically for OCR jobs.

Scanners are rated in dots per inch (dpi), whereas cameras are rated in total pixels. Both scanners and cameras have an optical resolution (the real lens resolution) and an interpolated resolution computed by software. The higher the optical, the better.

Scanners are also rated by the maximum color depth of each pixel (how many colors can be stored). At minimum, scanners support 24-bit color, and many go up to 48 bits. See optical resolution, interpolated resolution, 4K resolution, document scanner, flatbed scanner, sheet-fed scanner, handheld scanner, drum scanner, slide scanner, photo scanner and digital camera.


Desktop Scanners
The flatbed scanner is the most common desktop scanner. A transparency adapter provides a light source from the top for scanning 35mm slides and film negatives. Slide scanners are specialized for only slides and film (see slide scanner).







High-End Drum Scanner
Drum scanners are used for commercial graphics production and applications that require the highest quality scanning (see drum scanner). This earlier Howtek scanner provided an optical resolution up to 4,000 dpi. (Image courtesy of Howtek, Inc.)
References in periodicals archive ?
Software on the fingerprint scanner integrates with a Microsoft Active Directory server and authenticates the user against a local database.
The value of shipments for batch processing scanners reached $128 million in 1999.
With up to 100 profiles/second the tire scanner measurements can be as dense as desired.
They generally don't produce as sharp an image as a stationary desktop scanner because they must be maneuvered manually over the image.
In 2004, the US pen scanner market will hit $109 million.