Glossary

Baffled by scanner Gobbledegook?

Our scanner glossary is the answer to Technobabble!

One of the more dificult things about buying your first large format scanner is making sense of what the salesperson is saying. Some seem determined to confuse you!

Based on our experience of buying our first scanner and later selling them, we've compiled this glossary for anyone stumped by the gobbledegook of the major manufacturers' technical literature and the technobabble of wide format salespeople.

If you have suggestions for its improvement, please advise us. Thanks!

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The material in this glossary is the copyright of Softcover International Limited.

If you want to use this glossary, please email info@scanners4cad.com. This glossary may not be copied or used in full or in part without our written permission, an acknowledgement of Softcover International Limited's copyright and a link to this website. Thank you!

GLOSSARY

Gobbledegook - technobabble; the language of turkeys and technocrats; unintelligible, esoteric technical language used by salespeople to describe scanners, their features and performance; the major manufacturers' brochures and technical literature are prime examples of such, the understanding of which is aided by reference to this glossary.

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z

1-bit - raster image containing 2 colours, usually black and white.

2D LED - an integrated light emitting diode that beams light onto the scanned media from two directions, not one.

8-bit - greyscale raster image containing 256 shades of grey ranging from pure black (0) to pure white (255) with 254 grey shades in-between.

8-bit colour - colour raster image containing 256 colours.

24-bit - colour raster image containing over 16.7 million colours.

48-bit - colour raster image containing over 281 trillion colours. Most modern large format scanners scan in 48-bit mode and save in 24-bit mode after taking "the best" 16.7 million colours out of the original 281 trillion.

A

A-size - international standard metric drawing sizes typically ranging from A4 to A0.

accuracy - see geometric accuracy.

adaptive thresholding - the same as simple thresholding but instead of using one threshold value over the whole image, the image is divided up into local areas and a different threshold value is used in each local area. See thresholding.

ADF - automatic document feeder.

AEC - architecture, engineering, construction. A category of CAD.

annotation - comments attached to a scanned drawing or CAD file, also called mark-up or redlining.

ALE - Accuracy Lens Enhancement, a Contex patented technology for the electronic correction of spherical errors in its CCD based camera-scanning systems and the maintenance of precision across any two points of the scan line.

ANSI - American National Standards Institute. Determines US paper sizes like ANSI A to E-sizes.

anti-aliasing – a method of smoothing jagged pixel outlines that adds additional fainter pixels around the edges to create the illusion of a smooth outline. Mostly used in graphics software. Not recommended for scanned CAD drawings.

archiving - the process of scanning and storing old legacy paper drawings for future use. Often done to reclaim storage space.

aperture cards - an early drawing storage media involving a combination of punch cards and microfilm. A cut-out aperture on the card contains a 35mm microfilm image, typically a technical drawing. Info about the drawing, such as title, version, date, etc., is punched into the card.

aperture card scanner - device for scanning old aperture cards and saving them in raster file format.

Architectural D Size / D-size - 24 x 36 inches. US.

Architectural E Size / E-size - 36 x 48 inches. US.

array - a group of elements such as CIS sensors found in Colortrac and Graphtec scanners.

aspect ratio - the relative proportion of width to height of an image.

artefact - any unwanted feature in a scanned image, like speckles or noise.

auto-size - a scanner's ability to automatically detect the size of a drawing sheet.

automatic document feeder - ADF. A tray for automatically feeding a stack of drawings into office A4 - A3-size flatbed scanners. Generally unavailable in large format scanners.

B

ballast - see lamp ballast

batch - predefined actions carried out automatically and consecutively on a group of files.

bit - the abbreviation for "binary digit", either 0 or 1. Used in the description of colour depth. For example, in a 1-bit raster image each pixel is represented by 1 bit which can either be black (0) or white (1). In an 8-bit image each pixel is represented by 8 bits giving 256 combinations of 1s and 0s that represent 256 colours. A 24-bit image uses three 8-bit channels (red, green and blue - RGB) making over 16.7m colours (256 x 256 x 256).

bit depth - see colour depth.

bitmap - BMP. An uncompressed raster file format.

blue-line - Diazo prints or whiteprints with blue lines on a white background.

blueprint - technical AEC or engineering drawing printed on paper showing white lines on a blue background, the result of the cyanotype contact printing process.

BMP - bitmap.

Böwe Bell + Howell (BB+H) - an Image Access OEM.

brightness - the amount of light being reflected off a scanned object.

C

CAD - computer-aided design.

calibration - the setting or correcting of a scanner, usually by adjusting it to match or conform to a dependably known and unvarying measure. In colour calibration, the scanner and/or printer and/or monitor are adjusted so that printed and viewed colours match the colours of the scanned original as far as possible.

CAM - computer-aided manufacture.

CCD - Charge-Coupled Device.

carrier sheet - clear plastic wallet that holds damaged drawings to prevent snagging when scanning; aka "skin".

capture - to record an image digitally either by taking a photograph or by scanning.

centre justified - scanner that aligns the drawing from the centre of the scanner.

charge-coupled device - CCD. An image sensor consisting of an integrated circuit containing an array of linked or coupled capacitors sensitive to light. Established method of scanned image capture using a combination of lights, lenses and mirrors to capture light reflected from a scanned image.

chromatic - having to do with colour or colours.

chromatic aberration - an unfocused appearance in an image caused by a scanner's inability to accurately capture and distinguish different colour wavelengths.

CIS - Contact Image Sensor.

clamshell / clamshell design - a description used by Colortrac to describe the unique design and shape of their Ci 40 wide format scanner range; a sub-assembly containing CIS sensors injection moulded to fit around a single solid roller.

cms or cm/s - centimetres per second. A measure of scanner speed.

CMYK - Cyan, Magenta, Yellow and blacK. A colour model in which all colours are a mixture of these four process colours. The standard colour model used in full colour offset printing or four-colour printing. NOT to be confused with RGB.

CNC - computer numeric cutting. Cutting of shapes and profiles from metal, etc.

Colortrac - an innovative British manufacturer and marketer of large format scanners.

colour balance - an image's overall colour bias toward a primary or secondary colour.

colour cast - an undesirable tint to a colour image.

colour correction - removal of undesirable cast or tint from a colour image; process of ensuring that a scanned test sheet's colours are accurately captured, displayed and printed.

colour correction sheet - purpose-made test sheet for accurate colour sampling and correction.

colour depth – the number of colours that a device or image can hold or process. The greater the colour depth, the greater the number of colours and the greater the file size.

colour gamut - the range of different colours that a device can accurately capture. The more colours, the wider the colour gamut.

colour management - hardware and software techniques and processes used to maintain control of colour reproduction.

colour matching - properly converting scanned colours to the monitor's colours and to the printer's colours so that the colours that get printed look the same as the colours on the monitor and the colours on the original scanned document.

colour mode / model - how colour and tonal information is represented. Greyscale, Lab, HSL, RGB and CMYK are examples of colour models.

colour space - A subset of colours within a colour model that encompasses a particular gamut (range of colours). An example is sRGB. Converting scans from different scanners to a colour space like sRGB should make scans from different devices more similar.

compressed file - a file that has been reduced in file size by use of a software algorithm.

compression – technology that enables data to take up less space (a smaller file size makes data easier to store and faster to transmit). Image files can be compressed in two ways: lossless and lossy. When lossy compression is used, file quality is reduced. JPEG files use lossy compression and are therefore not recommended for storing CAD drawings.

contact image sensor - CIS. A linear array of detectors, covered by a focusing lens and flanked by LEDs for illumination. In contrast to using mirrors to bounce light to a stationary sensor, as in CCD scanners, the image sensor is placed in near direct contact with the object to be scanned. An innovation in the field of flatbed scanners but now increasingly used in large format scanners.

Contex - a Danish company, the biggest and most successful manufacturer of wide format CCD scanners worldwide.

contrast - the range between the lightest and darkest tones in an image; high contrast means a larger difference in brightness between the lightest and darkest areas as compared to low contrast.

coordinates - a set of numbers used to identify the location of a point in CAD.

Copy-to-Print - scanning images specifically for the purposes of printing them out; aka Scan-to-Print, Scan-to-Copy.

CopySmart - paid-for professional Scan-to-Copy software from Colortrac.

Corona effect - a blurring of the image; lack of sharpness.

CS500/600 - previous large format range of colour CIS scanners from Graphtec.

CS510/610 - current large format range of colour CIS scanners from Graphtec.

D

deep focus - Colortrac description of their CIS technology, intended to overcome early criticism that CIS scanners lack depth of field.

Delta-E (dE) - the mathmatical description of the "distance" between two colours; dE is a single number that represents the "distance" between two colours. (A dE of 1.0 is the smallest colour difference observable by the naked eye. A dE of less than 1.0 is imperceptible: a dE higher than 1.0 is noticeable).

density - the lightness or darkness of an image or a portion of an image.

depth of field - the range of distances away from the sensors that the paper can be in order for the scanned image to stay sharp. Applies particularly to folded and crumpled drawings.

desktop scanner - inexpensive small A4 - A3 flatbed scanner common in offices and homes.

despeckle - the automatic removal of unwanted dirt or noise from a drawing's background.

device driver - a software module that tells your operating system how to control a given piece of hardware, such as a scanner.

Diazo - prints or whiteprints which have blue lines on a white background; blue-lines.

dithering - method of simulating grey tones or colours in black and white images. Generally produces a very poor quality image. Not recommended for storing CAD drawings.

document carrier sheet - clear plastic wallet that holds damaged drawings to prevent snagging when scanning; aka "skin".

document management - the storage, indexing and control of digital documents.

dot - a unit used to represent the smallest element a printer can image, but sometimes used to represent the resolution of other devices, such as monitors or scanners.

dots per inch - DPI. The resolution of a printed page, expressed in the number of printer dots in an inch. Scanner resolution is also expressed

dpmdocuments/minute; usually refers to the number of A4 / legal size office documents which can be scanned at high speed by a document scanner (as opposed to a desktop or wide format scanner).

drum scanner - very expensive, extremely accurate scanner; overkill for CAD.

DPI - Dots Per Inch.

dynamic range - the ability of a scanner to capture smooth gradations of tone across the entire tonal range between black and white; how much detail a scanner can see in dark areas before 'blacking out'.

E

E size / E-size - largest US paper size, closely equivalent to A0 size.

EDM - Electronic Document Management. A computer based system used for managing electronic and paper-based documents; a means of checking documents and versions into a system and searching for them.

EDRMS - Electronic Document and Records Management System; allows RM rules to be applied to electronic documents as they are entered into such a system.

ENERGY STAR - ENERGY STAR and the ENERGY STAR mark are registered US marks. By qualifying to use and display this mark, a manufacturer meets the strict energy efficiency guidelines set by the US Environmental Protection Agency and the EC (European Community) ENERGY STAR Board for the prevention of greenhouse gas emissions.

enhanced resolution - interpolated resolution; a misleading description used by Contex.

extended resolution - interpolated resolution; a woolly description used by Colortrac which is neither misleading nor totally accurate.

F

File format - a description of the type of file; BMP, TIF, GIF and JPG are examples of different file formats.

Firewire - IEEE 1394 port. A method of connecting a scanner to a PC. Capable of very fast transfer speeds of up to 50 megabytes per second; faster than USB in optimum conditions.

firmware - control software built into or embedded into a hardware device.

flatbed scanner - scanner in which the sheet to be scanned is laid flat on a glass surface and the light source moves below the glass.

focussed image sensor - technology used in some CCD scanners which requires a focus distance of approximetely one metre between a drawing being scanned and the camera lenses.

folded optics - compact focussed image sensor technology using a series of staggered mirrors to "fold" the light source to create the necessary distance between a drawing being scanned and the camera lenses.

G

G600 - Contex designated scanner series, some of which were 508 dpi optical resolution; now replaced by current HD Series of 600 dpi optical resolution scanners.

gamut - see colour gamut.

geometric accuracy - the spatial accuracy of a scanned image compared to the original document. Affected by imaging technology, the drive system of the scanner, operating conditions and the medium being scanned.

GIF - Graphics Interchange Format. A compressed 256 colour graphic file format for the web. Not recommended for raster to vector conversion as it typically contains too little data to be useful.

GIS - geographic information systems.

gradation - a gradually changing range of tones from one colour or grey shade to another.

Graphtec - a Japanese company; a manufacturer of large format scanners and a wide range of other devices for the graphics, sign and apparel industries.

Graphics Interchange Format - GIF.

greyscale - an 8-bit raster image containing up to 256 shades of grey.

gsm - standard measure of paper thickness. The higher the gsm, the thicker the paper, card or board. 20 x 80 gsm sheets are 2mm thick.

GUI - Graphical User Interface - the method of interacting with a computer via a software program's graphical images, dialog boxes, menus and icons, etc.

H

half tones - artwork comprising shades of colour.

hand-held scanner - small scanner moved by hand; briefly popular but now less so due to problems of movement, quality and the stitching of several small images into a larger one.

HD - high definition.

HD Series - Contex's current range of CCD-based wide format scanners.

Hewlett-Packard (HP) - an American electronics giant that dominates wide format CAD printers. Hewlett-Packard does not manufacture scanners but is an OEM of Contex.

high-contrast - where the image's shades fall at the extremes between black and white.

hold down setting - adjustable value that determines the degree of pressure used to exert contact on a drawing sheet and the scan glass; setting will be less for torn or fragile drawing sheets.

HP - Hewlett-Packard.

HP scanners - Contex scanners badged with the HP brand name.

hyper threading - improves processor performance under certain workloads by providing useful work for otherwise idle execution units; Intel technology and trademark.

I

IEEE - Institute of Electrical and Electronics Engineers.

IEEE 1394 - see Firewire.

Image Access - the German manufacturer of the WideTEK wide format scanner range.

image quality - the combination of optical resolution, colour gamut, geometric accuracy and optical density.

image width - the size of that part of the drawing area containing detail to be scanned.

ins or in/s - inches per second; a measure of scanner speed. Aka ips.

interpolated resolution - resolution where the optical resolution has been increased (or decreased) by interpolation. Scanning at interpolated resolutions greater than the optical resolution makes images larger without adding original drawing detail or sharpness and is not recommended. Also called "extended" resolution (Colortrac) or "enhanced" resolution (Contex).

interpolation - a method of increasing or decreasing the resolution of an image by adding or removing pixels. When the resolution is increased new pixels are added between existing pixels and their colour is calculated on the basis of the colours of the pixels surrounding them.

ips - inches per second; a measure of scanner speed. Aka ins or in/s.

IS200 - large format range of CIS scanners from Graphtec.

ISIS - Image and Scanner Interface Specification. Industry standard scanner driver interface. Allows scanners to run at their rated speeds or higher.

IS0 - International Standards Organisation. Paper sizes like A4 to A0 are determined by ISO.

J

JPEG / JPG - Joint Photographic Experts Group. A compressed file format. Compresses images by decreasing image quality. Not recommended for scanned CAD drawings.

K

KIP - a Japanese manufacturer of wide format scanning and copying solutions. KIP manufacture the KIP 2200 large format scanner but OEM the 36" scanner in the KIP 3100 from Graphtec.

L

large format - any drawing size bigger than A3. Aka wide format.

large format scanner - any scanner larger than A3. Aka wide format scanner.

lamp ballast - an analogue electronics sub-assembly that drives fluorescent lamps; because scanners with fluorescent tubes cannot use a typical domestic circuit, (it will show up as interference fringes in the image), they use a complex, computerised electronic ballast to remotely control and or dim the light intensity.

landscape - orientation of a drawing in which the longest dimension is horizontal.

LED - light emitting diode; an integrated light source in CIS arrays; a digital technology much simpler to drive and control than older fluorescent tubes using lamp ballast.

legacy data - valuable historic data, documents and technical drawings.

legal size – US paper size; the equivalent of but smaller than A4.

line/mm - see line pairs per mm.

line art - images typically consisting of black and white lines or solid areas.

line pairs per mm - the number of black line to white lines that can be seen in the scanned image. The higher the number of line pairs, the greater the resolving power.

lossless compression - recommended method of image file compression without data loss; the image file is compressed and remains identical to the original data with no information lost in the process. TIFF is an image file format that can be compressed in a lossless way.

lossy compression - unsatisfactory method of file compression in which some supposedly redundant data in the original image file is lost when the compressed file is restored. JPEG or JPG is an image file format that is compressed in a lossy way; not recommended.

low contrast - where the image's shades fall close together across the image.

M

mark-up - the addition of comments onto a scanned drawing or CAD file, also called annotation or redlining.

media path - route of the drawing sheet through the scanner during the scanning process.

media width - maximum width of a drawing a large format scanner can feed into the media path.

microfiche - highly reduced, multiple images of documents on an index-card sized sheet.

microfilm - highly reduced images of documents on roll film.

MMI - man machine interface

monochrome - may mean black and white (two colours) or black and white AND greyscale.

multi-function - software capable of scanning, copying and printing.

mylar - an extraordinarily strong polyester film that can be used as an alternative to paper sheets which are easily damaged.

N

Newton's Rings / Newton Ring Effects - an interference pattern caused by the reflection of light between a spherical surface and an adjacent flat surface.

Nextimage - Scan and copying software for Contex scanners available in two versions. Nextimage SCAN is often included with the supplied scanner; Nextimage SCAN+COPY is an optional extra.

noise - undesired interference with the conversion of light during digital capture causing visible disruption to the integrity of the image; seen on a scanned image as dirt or speckles against what should be the drawing's clear white background.

O

OCR - Optical Character Recognition.

OEM - Original Equipment Manufacturer; a company which uses components made by a second company in its products or which sells the finished product of a second company under its own brand name.

on-site - in situ; where you or your scanner work.

optics - methods used for gathering and guiding electromagnetic energy, including lenses and mirrors.

Optical Character Recognition - the automatic process of converting scanned characters into editable ASCII characters or CAD text.

optical density - the ability of the system to reproduce black as a true, dense black.

optical resolution - the number of pixels per inch recorded by the scanner's image sensor. The greater the optical resolution, the greater the detail that can be captured from the image. The only resolution worthy of consideration.

out of gamut - a colour that cannot be reproduced accurately by the device processing the image.

P

paper media width - see media width.

paper thickness - maximum thickness of the sheet being fed through the scanner.

PDF - Portable Document Format

Portable Document Format - PDF. An open standard Adobe file format. Allows the representation of scans, CAD drawings, etc., to be shared with other people but not edited.

pixel - the smallest element in an image; refers to a single dot / square within a scan or digital photograph.

pixels per inch - PPI. The number of pixels per inch captured by a scanner, a more accurate term than dpi (dots per inch) as scanners capture pixels. A 10" by 10" image scanned at 100 dpi contains 10,000 pixels.

planetary scanner - essentially a mounted camera that takes pictures of documents placed beneath it. It is particularly suitable for fragile documents as it requires less contact with them than other types of scanner. Planetary scanners are often used for scanning rare books as these can be scanned spine down and do not need to be pressed flat against the scan glass.

PNG - Portable Network Graphics.

Portable Network Graphics - lossless file format; alternative to Graphics Interchange Format (GIF).

portrait - orientation of a drawing in which the longest dimension is vertical.

PPI - pixels per inch.

pre-press - the activities preceding the application of ink on paper by either traditional methods like printing plates or more modern electronic print-on-demand methods.

pressure plate - plate exerting downward pressure on a drawing sheet in order to provide best possible close contact between the scan glass and the drawing as it passes through a scanner.

Q

R

R2V - raster to vector conversion.

raster - an image made up of rows and columns of pixels of two (black and white) or more colours. Scanners save images as raster files. Typical raster file formats are BMP, TIF, PNG.

raster to vector conversion - R2V. Process of converting raster files into CAD-editable vector files. Often done automatically by raster to vector conversion software such as Scan2CAD. Aka vectorization.

rasterisation - process of converting vector images into raster files for storage, etc. the opposite of raster to vector conversion.

redlining - the addition of comments onto a scanned drawing or CAD file; also called annotation or mark-up.

repro - reprographics or reproduction. The business concerned with large format colour scanning, copying, sign-making and printing.

resolution - see optical resolution and interpolated resolution.

resolving power - the ability to differentiate fine image detail such as closely spaced contour lines on a map or fine lines in a CAD drawing. Usually measured in line pairs per mm.

revision control - the management of multiple revisions of a design.

rewind - ability to feed a drawing sheet back and forwards after scanning it

RGB - Red, Green, Blue. A colour model where colours are made up of red, green and blue. Used by display devices like monitors as well as scanners and many printers. NOT to be confused with CMYK.

RIP - Raster Image Processor. RIP software bypasses a printer's driver to take control of the printer directly to do a better job of colour management and to speed-up printing.

RoHS - Restriction of Hazardous Substances. An EU directive intended to protect the environment by forcing manufacturers to remove environmentally hazardous substances from scanners.

rollers - wheels that grip and propel the drawing sheet through a scanner.

rotation - the process of aligning a drawing into its true orientation.

ROWE - Roth+Weber, a German manufacturer of ROWE wide format scan and copy solutions.

rubber-sheeting - the transformation of spatial data to stretch or compress it to fit with other data, typically a map; a method to stretch or warp images to match existing vector data; edge matching; another name for warping software used to correct errors by stretching a scanned map to fit known control points.

S

SCSI - Small Computer Systems Interface; pronounced "skuzzy".

SCSI Scanner Interface - a standard for attaching up to seven peripherals (notably mass storage devices and scanners) to a PC. Now redundant due to success of USB.

Scan2CAD - trademarked industry leading automatic raster to vector conversion software from Softcover International Limited.

Scan2Net - trademarked technology from Image Access allowing high speed transfer of scanned data into existing network structures.

scan glass - hardened glass over which the drawing passes as it is illuminated during scanning.

scan time - the time required for a document to physically pass through a scanner; not to be confused with throughput.

Scan-to-File - scanning drawings and saving them directly into a folder, often with incrementally updated file names e.g. file1.tif, file2.tif, etc.

Scan-to-Copy - scanning images specifically for the purposes of printing them out; aka Copy-to-Print, Scan-to-Print.

Scan-to-Print - see Scan-to-Copy.

scanner - device for capturing images or text and converting them to a digital raster file.

Scanning Arts - multi-function scan and copy software supplied for Graphtec scanners.

Scanning Master 21+ - scanning software usually included with Graphtec scanners.

ScanWorks - paid-for scanning software from Colortrac.

SD Series - Contex's first generation of CIS-based wide format scanners.

signal / noise ratio - SNR. The ratio between a signal (meaningful information / image data) and the background noise (unwanted speckles, blurring, etc.). An electrical engineering concept defined as the ratio of a given transmitted signal to the background noise of the transmission medium.

side justified - scanner that aligns the drawing from the side of the scanner.

simple thresholding - Every colour has a numeric value. In a simple threshold you choose a single colour value, the threshold. All colours with colour values lower than the threshold are set to black and all colours with colour values higher than the threshold are set to white. See thresholding.

single solid roller - A unique feature of the Colortrac SmartLF Ci 40. Unlike conventional scanners with multiple rollers, it uses a single, precision-engineered drum or Advanced Single Roller Paper Transport system.

skin - clear plastic wallet that holds damaged drawings to prevent snagging when scanning. Aka document carrier sheet.

SmartLF - large format range of monochrome and colour CIS scanners from Colortrac; also basic scanning software supplied free with every SmartLF scanner.

SNR - signal / noise ratio.

solid state - circuits that do not contain moving parts.

speckles - unwanted dirt on a drawing's background.

speckle removal - the automatic removal of unwanted dirt or noise from a drawing's background.

sRGB - A standard colour space used by many scanners and digital cameras. Although a Hewlett-Packard and Microsoft initiative offers faster diplay times for objects in this colour space it is not recommended for all applications as its gamut is relatively narrow.

stabilisation time - see warm-up.

stitching - process whereby images created by different cameras or CIS arrays within a large format scanner are joined into one seamless image; post scan process of joining small images into a larger one after capture with a hand-held scanner.

T

Tagged Image File Format - TIFF, TIF. Developed specifically for scanners. Used to store compressed black and white, greyscale and colour images without data loss. A graphic standard. Highly recommended.

threshold - predefined level determining whether a scanned pixel will be represented as black or white.

thresholding - useful scanner or software tool for tidying up an image by cleaning (whitening) the background while strengthening (blackening) the foreground drawing detail. See simple thresholding and adaptive thresholding.

throat - the maximum paper or media width that can be fed into a scanner. This is different from scan width.

throughput - a measure of the time the entire data capture process takes; the total time taken to scan a document from start (feed) to finish (saved).

TIFF, TIF - Tagged Image File Format

touch panel - control panel on scanner that allows simple control of scanning, paper feed, etc.

transoptipolation - resolution that uses a mix of optical resolution in one direction and interpolated resolution in another.

turbo mode - In 400 dpi turbo mode, the scanner scans at 400 dpi optical along the width of a drawing and at 200 dpi optical along its length. After scanning, the 200 dpi is automatically interpolated back to 400 dpi. This is faster than scanning the length at true 400 dpi optical but results in a loss of quality.

TWAIN - standard software protocol regulating communication between software applications and popular imaging devices like scanners.

U

USB - Universal Serial Bus. See USB1 and USB2. An alternative to Firewire.

USB1 - first release of an advanced, fast serial interface supporting large numbers of "plug and play" devices. Intended to take the pain out of adding peripheral devices to a computer. Maximum data throughput 1.5MB per second.

USB2 - the latest release of the USB standard with a maximum throughput of 60MB per second, USB2 is 40 times faster than USB1.

V

vector - A scaleable image using mathematical coordinates to define the start and end points of each line, etc. Unlike a raster image, it can be edited in CAD.

vectorization - see raster to vector conversion.

Vidar - a scanner brand name. Previously a respected large format manufacturer, Vidar is now owned by Contex who sell their scanners under the Vidar name.

W

warm-up - time it takes a scanner to become ready for use. CCD scanners take longer to warn up than CIS ones.

warp / warping - A raster editing tool to deform a raster image by moving specified points on the image together with all the attached points. See rubber-sheeting.

warp speed - scanning true optical resolution on the width, but scanning only half the "lines" in the length; a feature of very old, now redundant Vidar and Colortrac scanners intended to provide quality and speed. See Contex's turbo mode.

WEEE - Waste Electrical and Electronic Equipment; the WEEE Directive is EU legislation which sets collection, recycling and recovery targets for all types of electrical goods. It places responsibility for the disposal of WEEE on the manufacturer.

WIDEimage - paid-for scanning software from Contex.

wide format - any drawing size bigger than A3. Aka large format.

wide format scanner - any scanner larger than A3. Aka large format scanner.

workflow - a description of business practice and processes. Workflow products automate repetitive tasks, specifically the processing of documents and drawings through a business.