HP Glossary of scanning terms and definitions

Glossary of Terms
[Based on Internet sources]

A
aberration	The failure of a mirror, refracting surface, or lens to produce exact, point-to-point correspondence between an object and its image.
access hatch	The cover over the top of the ADF feed mechanism that is opened to remove jammed paper.
accessory connector socket	The circular socket labeled ADF/ACC on the back of the scanner where the connector cable is inserted.
acquire	A menu item typically under File that allows you to start the scanning software directly from the application. Acquire is only available if the software is TWAIN-compliant.
actual size	The size of the page when it was scanned (not enlarged using zoom in or reduced using zoom out).
ADF (Automatic Document Feeder)	A scanner accessory that automatically feeds a paper stack to the scanner.
ADF window	A clear plastic strip on the bottom of the ADF that provides access to the scanner optics. This window must be clean and undamaged in order to obtain high-quality scanned images using the ADF.
Advanced SCSI Protocol Interface (ASPI)	An interface standard developed by Adaptec Inc. that has become one of the major SCSI interface standards for computers.
aliasing	Reflections of higher frequencies at about the sampling rate of a scanner that cause unwanted effects such as Moirй patterns in an image. These patterns, called artifacts, look like two geometrically regular patterns such as two sets of parallel lines or two halftone screens superimposed. See also artifacts, Moirй pattern.
American National Standards Institute (ANSI)	The institute that developed the SCSI interface standard.
annotation	A word, note, mark, or highlighting added to an item.
Annotation Tool Bar	A group of icons that represent the tools used to add annotations to a PaperPort (TM) software Page. The Annotation Tool Bar is only available in Page View.
array	A grouping of like elements. See also CCD.
Arrow tool	An Annotation tool for drawing straight lines with or without arrowheads.
artifact	A reflection of higher frequencies at about the sampling rate of a scanner that appears as an unwanted pattern in an image. See also aliasing, Moirй pattern.
Autoexec.bat file	A text file containing a set of commands that the computer carries out whenever it is started or restarted. The Autoexec.bat file is typically used to load programs automatically that need to be on your system when it is running.
automatic document feeder (ADF)	A separate part that attaches to the scanner and feeds multiple page documents to the scanner.
B
batch scan	The process of scanning numerous page that contain similar data; for example, a number of photos or a multiple-page text document.
beat frequency	A periodic variation in a signal resulting when two signals of unequal frequencies are combined. Where the beat is maximum the signal and the samples line up perfectly and the resolution is high. But where the beat is minimum the signal and the samples do not line up and the resolution is low.
bit depth	The number of bits used to process scanned images. The greater the number of bits, the more colors or levels of gray that can be used to display the image.
bitmap	A dot-by-dot representation of an image. Bitmapped images are made up of one bit of color (black or white) per pixel, and require the least amount of disk space.
black and white drawing region	A region of a view area of the scan used for areas with only black and white lines or shapes. Photos show depth, while drawings are flat. A drawing region is also used to capture text that includes graphical elements (like a logo) as an image.
black and white photo region	A region of a view area of the scan used for areas that include an image with shades of gray in addition to black and white. Photos show depth, while drawings are flat.
black point	The color that when scanned produces values of 0, 0, 0 in an 8-bit scanner. Ideally, the black point is 0% neutral reflectance or transmittance. See also white point.
BMP file	A Microsoft (R) Windows bitmap file that has the extension ".bmp". A bitmap file defines an image (such as the image of a scanned page) as a pattern of dots (pixels).
border	A boundary around a region indicating a specific area for the HP PrecisionScan software to transfer to a destination. The border must be selected for the region to be transferred to the destination. Borders are either created automatically or by the software or drawn manually.
brightness	A measure of the overall intensity of the image. The lower the brightness value, the darker the image; the higher the value, the lighter the image will be.
C
calibrate	To standardize by determining the deviation from a standard so as to find the right correction factors.
CAM (Common Access Method)	An ANSI standard interface for SCSI controllers.
carriage	A scanner's imaging head that moves down a page to capture an image. Also called optical imaging element, optical imaging head.
CCD (charge- coupled device)	A miniature photometer that detects light intensity and represents the intensity with an analog voltage. A CCD array is made up of CCD elements, the smallest discrete CCD.
chroma	A quality of color combining hue and saturation. See also hue, saturation.
*CIELAB (Lab)**	A color model to approximate human vision. The model consists of three variables: L* for luminosity, a* for one color axis, and b* for the other color axis. CIELAB is a good model of the Munsell color system and human vision.
clipping	The assignment to a cutoff value of all the samples that are above or below that cutoff in the input. The result is that any input detail in that portion of the intensity spectrum is lost in the output.
closed loop	A signal path that includes a forward path, a feedback path, and a summing point, and that forms a closed circuit. collapse The process of reducing a sticky note to an icon.
CMYK color	CMYK images consist of the four colors used to print color separations. They are four-channel images, containing 32 (8 x 4) bits per pixel.
color drawing region	A region of a view area of the scan used for areas with a few solid, uniform colors (like a cartoon or a logo). Photos show depth, while drawings are flat. A drawing region is also used to capture text that includes graphical elements (like a logo) as an image.
color matrixing	*See 3-by-3 matrixing.*
color mixing	*See 3-by-3 matrixing.*
color photo region	A region of a view area of the scan used for areas that include an image with color graduations in addition to blocks of solid, uniform color. Photos show depth, while drawings are flat.
color-matching functions	The mathematical relationships that assign a weight to red, green, and blue color separations to reproduce the original color. 3-by-3 matrixing is the use of a color-matching function available on some scanners. See also 3-by-3 matrixing.
Command Bar	A group of icons on the PaperPort software Desktop that are shortcuts for commands available in the PaperPort software menus.
Common Access Method (CAM)	An ANSI standard interface for SCSI controllers.
Config.sys file	A text file containing configuration commands used when you start the computer. Commands in this file enable or disable system features, set limits on system resources, and extend operating system capability by loading device drivers. configuration work diskette A diskette used by EISA computers to store the system configuration.
connector cable	The cable connecting either the transparency adapter or the ADF to the scanner.
container program	A program into which an object linking and embedding (OLE) object is inserted. That program contains the object.
continuous tone	An image such as a photo or a painting that has a range of tones or a gradation of tones.
contrast	The difference between the dark and light areas of an image. The lower the number value, the more closely the shades will resemble each other. The higher the number, the more the shades will stand out from each other.
copyboard	The flat glass plate on which originals are placed for scanning.
copyboard cover	The cover of the scanner that holds papers flat for scanning or is removed before the transparency adapter is installed.
copyboard glass	The glass surface on top of the scanner where a document is scanned.
correlated noise	A recognizable pattern of change in an image file. The change is an increase or a decrease in the brightness of the pixels compared to what they should be. The pattern can be horizontally across a raster line, vertically down through the raster lines, or diagonally down and across the raster lines. Vertical correlated noise is often called streak noise and is a common problem with CCD technology. Also called periodic noise. See also noncorrelated noise.
count	An increment or decrement of l in the analog-to-digital converter connected to a CCD element in a scanner. A count represents the difference of l gray level as perceived by a scanner.
crop	To remove part of an image in Page View. The portion of the image that is selected remains, while the portion that is not selected is removed.
crosshair cursor	A cursor in the shape of a plus sign (+). This cursor appears when you use certain Annotation tools.
D
dark voltage	The voltage from a CCD when no light is incident on the CCD. Also called dark current.
density	A measure of reflectance or transmittance equal to log10 (1/reflectance) of log10 or (1/transmittance).
density range	*See dynamic range.*
depth of field	*See focal range*
deskew	To straighten a crooked page or image. The HP PrecisionScan software automatically deskews pages placed on the scanner bed at less than a 10 degree angle.
Desktop View	The overall view of your PaperPort software items, with thumbnails (small graphic representations) showing the pages and stacks as if spread out on a desktop.
destructive interference	The condition that results when two signals combine and cancel each other out.
device driver	Software that the system uses to communicate with devices such as a display, printer, mouse, or scanner.
DIB (Device- independent bitmap ) format	A common bitmap format for Windows applications.
diffuse dither	A method for printing continuous-tone images on laser printers in which the grayscale information is represented by randomly located printer dots. Diffuse dithers do not photocopy well because of the small, random, dot location in the image.
diffuser	The translucent-white, acrylic sheet on the bottom of the transparency adapter that evens out the light coming from the lamps inside the transparency adapter.
dithering	Creating halftone dots by combining the printer dots in a halftone cell. A printer's halftone cell is the equivalent of the halftone dots produced by traditional halftone screening. *See also halftone cell, halftone dot.*
document guide	The green plastic bar across the top of the ADF where paper is positioned when loaded into the input tray.
document management	An integrated system for handling the electronic storage, retrieval, analysis, communication, and management of digitized images of paper documents.
dot	See halftone dot, printer dot.
dots per inch (dpi)	A measurement of resolution used for scanning and printing. Generally, more dots per inch mean a higher resolution, a greater amount of visible detail in the image, and a larger file size.
driver	A low-level program that controls a piece of computer hardware. Also an electronic circuit that supplies input to another electronic circuit.
dropout color	A color that is invisible when scanning a color object in grayscale mode, causing any detail in this color to disappear.
duotone	Duotone mode is used for monotones, duotones, tritones, and quadtones. These images are grayscale, single-channel images with 8 bits per pixel.
dynamic range	The range of the lightest to the darkest object that a scanner can distinguish. Also called density range.
E
editable text	Text that is converted from a scanned image into characters that you can modify in a word processor or other text editing program. Depending on the capabilities of your text editing program, you can change the font, size, style, and other attributes of editable text, and you can edit words or phrases of the text to meet your needs.
e-fax (electronic fax)	The software that you use with a modem for sending a fax. See the glossary term "fax" listed below for more information.
EISA (Extended Industry-Standard Architecture)	A bus standard introduced in 1988 and intended to provide greater performance than ISA and still be compatible with all ISA cards.
electronic mail (e-mail)	Software that you can use to electronically transmit items over a communications network.
expand	A process to restore a collapsed sticky note from an icon to its original size.
export	A function that allows you to save a copy of a PaperPort software item as a backup or in another graphics format, such as a .tif, .gif, or .jpg.
F
fax	An abbreviation for facsimile. The electronic encoding of a printed page and the transmission of the electronic page over a telephone line. The PaperPort software can send items to electronic fax programs, which require a modem and fax software.
feed mechanism	The mechanism located on the right side of the ADF that feeds the paper from the input tray to the transport belt.
file format	The way the contents of a file are structured by a program or group of programs.
focal range	The portion of an object that is in focus. Also called depth of field.
folders	In the PaperPort software, distinct places where items are stored electronically, similar to file folders in a file cabinet. Up to 100 of these electronic folders can be created and named, and each can hold up to 100 items.
FPX Flaxhpix	An emerging World Wide Web standard for images. The FPX file format stores one version of the file for onscreen display and one for printing. This format is useful for a single image that you plan to place on the Web, if you want quick display and quality printing.
Freehand tool	An Annotation tool you use to draw a circle or any other shape on a PaperPort software page.
frequency response	See optical frequency response.
full-size transparency	A transparency sized up to 216-by-297 mm (8.5-by-11.7 in).
G
gamma	A mathematical curve representing both the contrast and brightness of an image. Moving the curve in one direction will make the image both darker and decrease the contrast. Moving the curve the other direction will make the image both lighter and increase the contrast.
gamma correction	A form of tone mapping in which the shape of the tone map is a gamma. *See also gamma curve, tone map.*
gamma curve	The mathematical function y = x' that describes the nonlinear tonal response of many printers and monitors. The compensating function is y = x 1/'. A tone map that has the shape of this inverse function cancels the non-linearities in printers and monitors. See also gamma correction.
gamut	The range of colors that can be captured or represented by a device. When a color is outside a device's gamut, the device represents that color as some other color.
GIF (Graphics Interchange Format)	An image used by CompuServe and other online formats.
grayscale	Shades of gray that represent light and dark portions of an image. Color images can also be converted to grayscale where the colors are represented by various shades of gray. Images are made up of 8 bits of imformation per pixel and use 256 shades of gray to simulate gradations in color. You can add new channels to a Grayscale image.
H
halftone	An image type that simulates grayscale by varying the sizes of the dots. Highly colored areas consist of large color dots, while lighter areas consist of smaller dots.
halftone cell	A square area in a halftone grid that holds an array of printer dots. A halftone cell can represent a discrete number of gray levels equal to the maximum number of printer dots that the halftone cell can hold, plus l. See also halftone dot.
halftone dots	Different-sized black dots produced by turning particular dots on and off during printing, either on a laser printer, an image setter, or a printing press. The dots repeat in a regular pattern, creating the illusion of continuous tone. Halftone dots are not the same as printer dots. See also printer dot.
harmonic	A component of a signal whose frequency is an integral multiple of the signal's frequency.
highlight	The brightest part of an image.
Highlighter tool	An Annotation tool that works in the same way as a highlighter marker. This tool adds a color over selected areas of a page.
histogram	A bar graph for variables measured at the interval and ratio levels. A histogram has one axis showing the number of samples for each specific intensity level. A histogram shows the portions of the intensity spectrum where the image information is concentrated hue. The color mixed from red, green, and blue. See also chroma, saturation.
I
I/O addresses (Input/Output addresses)	Locations within the input/output address space of your computer that are used by devices such as printers, modems, or scanners. I/O addresses are used for communications between software and the device to which the address is assigned.
identity tone map	A one-to-one mapping of the input values to identical output values without changes in contrast or brightness. See also nonidentity tone map.
image editor	An application that allows you to modify bitmapped drawings and photographs. Some image editors have more editing tools and accept a wider range of image types than others.
image type	The different representations of an original that can be captured by a scanner For instance: 24-bit color, 8-bit grayscale, or l-bit drawings.
imaging element	*See carriage.*
imaging mode	Refers to the dithering of an image as it is scanned. With this scanner, the mode can be error diffusion (photographs and graphics) or threshold dithering (text).
import	A function that allows you to bring files saved in graphics formats such as .bmp and .tif into the PaperPort software.
indexed color	Indexed color images are single-channel images (8 bits per pixel) that use a color lookup table containing 256 colors. Limited editing is available in this mode; for extensive editing you should convert temporarily to RGB mode.
Industry-Standard Architecture (ISA)	An unofficial designation for the bus design of the IBM PC/AT.
input tray	The top surface of the ADF where documents are loaded before being fed into the scanner.
instrument metamerism	A phenomenon in a scanner in which two colors that look the same to an observer look different to the scanner, or two colors that look different to an observer look the same to a scanner. Instrument metamerism is an non-recoverable error because based on the output, there is no way to determine what the input was. See also non-recoverable error.
intensity	The amount of light reflected or transmitted by an object with black as the lowest intensity and white as the highest intensity. interpolated sample A sample that is created by interpolation as opposed to real samples that are created during the scan.
interpolation	The process of creating estimated values between known values. In scanning, interpolation can be used to increase the number of samples by adding the estimated samples to the real samples. Or it can be used to decrease the number of samples by creating an estimated sample from two or more real samples and discarding the real samples.
Interrupt Request Line (IRQ)	A hardware line over which devices can send signals indicating that they are ready to send or receive information (interrupts). Each device that uses interrupts should use a separate IRQ to avoid conflicts.
irreversible transformation	A change in an image during scanning and postscan image editing in which information about the image is irretrievably lost.
item	A page or a stack of pages on the PaperPort software Desktop.
J
jaggies	The stairstep effect in diagonal lines or curves that are reproduced digitally.
Joint Photographic Experts Group (JPEG or JPG)	An international standard for compressing digital photographic images.
just-noticeable difference	In the CIELAB color model, a difference in hue, chroma, or intensity, or some combination of all three, that is apparent to a trained observer under ideal lighting conditions. A just-noticeable difference is a change of l; a change of 5 is apparent to most people most of the time. *See also CIELAB.*
L
legal extension	A separate part attached to the scanner that holds legal-size pages in place for scanning.
Like differences	Differences in color or lightness that are of similar magnitude to the average observer.
Line drawing	A drawing that consists only of black and white with no intermediate grayscale information.
Line dropping	Subsampling to reduce the number of raster lines in an image by dropping every nth raster line from the scan. See also pixel dropping.
Line replication	Creating more raster lines than are actually scanned by replicating every nth raster line from the scan. See also pixel replication.
Linearity	The degree to which the input of a signal is proportional to the output.
link	A connection to a program or device that you can use to send information from the PaperPort software to other programs, such as e-mail, e-fax, and optical character recognition (OCR) links.
Link Bar	The icons on the bottom of the PaperPort software Desktop View that represent programs installed on your computer, such as e-mail software.
link preferences	The options, such as what program and which file format, you choose to associate with a particular link. These preferences can be customized depending on the software installed on your computer and your needs for the final file format.
linked program	A program installed on your computer that you can use with the PaperPort software. For example, you can use OCR software to translate a PaperPort software item into text.
Lpi	Lines per inch.
Lppi	Line pairs per inch.
M
magnetic latches	The latches that hold the front end of the ADF down on the scanner during ADF operation.
Mark-Up tool	An Annotation tool designed for adding text to preprinted forms which are scanned into the PaperPort software. You can search for words in a mark-up by using the Find command.
metamerism	*See instrument metamerism.*
Micro Channel	A bus standard introduced by IBM and intended to provide greater performance than the ISA bus. Accessory cards for ISA bus computers are not compatible with Micro Channel computers.
midtones	Tones in an image that are in the middle of the tonal range, halfway between the lightest and the darkest tones.
ModulatedTransfer Function (MTF)	A test that measures the optical frequency response of a scanner or other optical system. *See also transfer function.*
Moire pattern	An unwanted effect that appears in scans of printed images or other high-frequency scans. Moire patterns are reflections of the high-frequency components of an image that are at about the sampling rate of the of the scanner. Moire patterns are a kind of aliasing and are also called artifacts. See also aliasing, artifacts.
mounting posts	The hinged posts on the back of either the transparency adapter or the ADF that are inserted into the scanner body during installation.
Munsell color system	A system consisting of over 3 million observations of what people perceive to be like differences in hue, chroma, and intensity. The participants chose the samples they perceived to have like differences. See also CIELAB, chroma, hue, saturation.
N
noise	A distortion of an image's analog signal. This distortion can be correlated or noncorrelated. Noise is an analog problem that is confined to the analog electronics in a scanner. Once a signal is digitized, it is relatively immune to noise. *See also correlated noise, noncorrelated noise.*
noncorrelated noise	A random distortion in an analog signal causing snow or speckles--random spots throughout the image. The distortion can be the result of electronic noise in the amplifiers, electrical spikes somewhere in the system (the scanner, printer, or monitor), or random fluctuations in the scanner lights. Also called random noise. See also correlated noise.
nonidentity tone map	The mapping of the input data from the scanner to the output data with tonal transformation. Nonidentity tone maps are used for exposure manipulation, gamma correction, and mapping l0-bit data to 8-bit data.
non-recoverable error	A deviation from the original color in an image that cannot be corrected by a mathematical operation using a color-matching function. See also color-matching function, recoverable error.
Nyquist frequency	The maximum frequency that can be sampled by a digital sampling device such as a scanner. The Nyquist frequency of any digital sampling device is l/2 the sampling rate of the device. To capture full information about a signal, the frequency content of the signal must be significantly below the Nyquist frequency of the device.
O
object	A graphic or picture that is embedded in a document file by using Object Linking and Embedding (OLE). A scanned picture can be an object.
object linking and embedding (OLE)	An industry-standard method for inserting an object into a document. The document retains a connection, or link, with its original program so that double-clicking on the object in the document opens the object's original program.
OCR (Optical Character Recognition)	A technology that can recognize letters from a scanned image and convert them into ASCII characters to be saved as an editable text file.
Offset voltage	DC potential remaining at the input terminals in the amplifier when no output voltage is present.
Optical filtering	Selectively transmitting or blocking a range of wavelengths.
Optical frequency response	A scanner's capability for capturing a given frequency or range of frequencies.
Optical sampling rate	The number of samples, in pixels per inch, that are taken by a scanner per linear distance as determined by the CCD array, the optical system, and the motion of the carriage. Optical sampling rate can be changed by interpolation or subsampling and no longer be the scanner's true optical sampling rate. Optical sampling rate is not the same as resolution. Also called ppi rate. See also resolution, sampling rate.
Outlying value	A unit of analysis that has extreme values on a variable. Also called outlier.
output tray	The sloping tray on the left side of the ADF that holds the paper ejected after scanning is complete.
oversampling	Scanning at more than an optimum sampling rate. See also subsampling.
P
page	A PaperPort software term that refers to a one-sheet item or one sheet of a stack.
Page Navigator	The buttons you choose in Desktop View or Page View to move from page to page in a stack or to go to a specific page.
Page View	A close-up view of one page, which lets you read and annotate the page.
Pan tool	An annotation tool for quickly scrolling an image in Page View. When the pan tool is active, the cursor appears as a hand.
paper jam	A condition where a sheet of paper is not properly fed, causing an interruption in ADF operation.
paper load lever	The green, manually-operated lever used to load paper into the ADF input tray.
paper load window	The opening in the access hatch that makes it possible to view the registration stop. paper stack The stack of documents that are placed in the input tray and are fed by the ADF.
paper-transport belt	The large white belt on the underside of the ADF used to move paper from the ADF to the scanner glass.
Photo Response Non-uniformity (PRNU)	Pixel-to-pixel variation in the response of a CCD array to a fixed-intensity light. Ideally, the response to each CCD element in the array is identical; deviations from that response are caused by PRNU.
photometer	An instrument for measuring luminous intensity, luminous flux, illumination, or intensity.
Periodic noise	*See correlated noise.*
Pixel	A pattern of dots that when combined create an image such as a bitmap.
pixel (PICture Element)	The smallest individual element in an image. For scanners: a pixel is the same as a sample.
pixel depth	*See bit depth.*
pixel dropping	Subsampling to reduce the number of pixels in an image by dropping every nth pixel from the scan.
pixel replication	Creating more pixels than are actually scanned by replicating every nth pixel to create the n+ 1 pixel.
pixelization	Graininess in an image that results when the pixels are too big.
Pointer tool	The tool on the Annotation Tool Bar for selecting an annotation to cut, copy, or paste.
ppi (pixels per inch)	Ppi is often used interchangeably with dpi, although a dot is a bilevel entity, either on or off, and a pixel can hold multiple levels of information. For instance, for an 8-bit scanner, 1 pixel has 256 possible values (0 to 255). In this book, ppi is used for devices that use multilevel samples such as scanners. See also dpi.
ppi rate	*See sampling rate.*
printer dot	The individual pixel in a halftone image. The size of a printer dot is variable, ranging from zero (all white) to the size of the halftone screen (all black). See also halftone cell, halftone dot.
PRNU (Photo Response Non-uniformity)	Pixel-to-pixel variation in the response of a CCD array to a fixed-intensity light. Ideally, the response to each CCD element in the array is identical; deviations from that response are caused by PRNU.
Q
quantization	The artificial forcing of like gray levels to the same gray level as a result of limited tonal resolution in a scanner. Quantization is most often seen in the shadow portion of scanned images. See also tonal resolution.
R
random noise	*See noncorrelated noise.*
raster line	A thin horizontal strip across an image. Raster lines are captured one at a time by the CCD elements in a scanner. When displayed or printed in sequence, raster lines make up the image. Raster lines in a TV or monitor work the same way.
recoverable error	A deviation from the original color in an image that can be corrected by a mathematical operation using a color-matching function. See also 3-by-3 matrixing, color-matching function, nonrecoverable error.
reflectance	The fraction of the light incident on a surface that is reflected and varies according to the wavelength distribution of the light. Also called reflectivity.
reflectance linearity	The degree to which a plot of scanned reflectance or transmittance vs. absolute reflectance or transmittance is a straight line. Deviations in this plot either above or below a straight line represent tones that are recorded by the scanner as too light or too dark, respectively.
region	A distinct area of a scan. A region is either a text, photograph, or drawing region type.
region tool	A tool used to select or clear an automatically-identified or previously-created region. The region tool is also used to manually create a border, adjust borders, and drag and drop a region to a destination.
registration stop	The green, plastic post, visible through the paper load window, used to properly position a paper stack when it is loaded into the input tray.
RGB color	RGB images use three colors to reproduce up to 16.7 million colors on-screen. RGB images are three channel images, so they contain 24 (8 x 3) bits per pixel.
resolution	The degree to which a scanner distinguishes detail in an object. Resolution is affected by sampling rate but also by other aspects of a scanner such as lens quality, filter quality, and the motion of the carriage. See also carriage.
resolution	The sharpness of an image, measured in dots per inch (dpi). The higher the dpi, the greater the resolution.
RTF Rich text format	This format is common for word processors. It accepts both text and images, and retains text formatting and page layout.
S
sampling rate	The number of samples, in pixels per inch, that are created by a scanner per linear distance. In this book, sampling rate means the optical sample rate changed by interpolation or subsampling. Also called ppi rate. See also optical sampling rate.
saturation	The amount of color in a specific hue. See also chroma, hue.
saturation level	Light intensity that exceeds the maximum level designed for a CCD.
scale	To enlarge or reduce an image by increasing or decreasing the number of scanned pixels, or the sampling rate, relative to the number of samples per inch needed by the printer or other output device. See also interpolation.
scanner bed	The plastic housing that supports the scanner glass.
scanner button	The green button on the front of your scanner. By default, the scanning software opens when you press this button, but you can specify a different action to be performed each time you press the scanner button.
scanner cover	The cover of the scanner that is removed before the ADF is installed.
scanner glass	The glass surface on top of the scanner where you put items to scan.
SCSI (Small Computer System Interface)	An interface that lets you attach hard disks and other high-performance peripherals to computers.
Selection tool	An Annotation tool used to select part of an item to cut and paste to the Clipboard. separation pad Rubber-like pad under the ADF hatch used to separate pages as they enter the ADF.
shadow detail	Subtle features in the darker part of an image.
sharing	The act of scanning documents into your computer and sending those documents to someone else using e-mail, e-fax, or some other software. These documents can be edited using the PaperPort software.
sharpening	An option on some scanners that emphasizes detail by increasing the contrast of the boundaries between light and dark areas of an image.
signal-to-noise ratio	The ratio of the usable signal to unusable noise in a scan. A high degree of noise can mask the shadow detail in an image regardless of tonal resolution. See also noise, shadow detail, tonal resolution.
sinusoidal	Relating to a sine wave.
spectral sensitivity	The relationship between the radiant sensitivity and the wavelength of incident light.
stack	A PaperPort software item with two or more pages.
standard colormetric observer	An entity described by the CIELAB color model consisting of three spectral-sensitivity curves called color-matching functions. See also CIELAB, color-matching function, spectral sensitivity.
standard deviation	A measure of dispersion of a frequency distribution.
sticky note	An annotation that is a multiline, resizable note. Similar to a paper sticky note, it covers the item information beneath it. You can move a sticky note or collapse it to an icon. You can search for words in a sticky note by using the Find command.
streak noise	Vertically correlated noise in a scan. See also correlated noise.
subsampling	Scanning at a less than optimum sampling rate. See also oversampling.
summary information	Information about the item, such as the creator or keywords, which can be added in the Summary Information dialog box to help you find the item quickly.
T
target	In the context of testing, the portion of the original to be scanned.
terminator	A device that prevents data signal reflection from the end of an electrical conductor. This ensures that the reflected signals do not mix with the primary signals and confuse any devices that need the data being sent on the conductor.
text region	A region of a view area for which the HP PrecisionScan software converts the resulting image into editable text characters. If you want the text as an image instead, transfer the text to a destination that accepts only images.
the PaperPort software Viewer	A type of software that allows someone who does not have the PaperPort software to view a PaperPort software document. The Viewer does not allow someone to change the document.
threshold	A value to which a signal is compared when transforming from a multilevel value to a binary value. In a binary scan, parts of the image below the threshold will be recorded as black and parts above the threshold will be recorded as white.
thumbnail	A small graphic that represents an item on the Desktop.
TIF (or TIFF) Tagged image file format	. This format is useful for storing photos and color drawings. Because TIF is a widely-used format for graphics, it is especially useful for graphics that will be sued in many applications or on more than one computer platform.
tonal resolution	The number of bits per pixel used in the digital representation of an image. The intensity and color of each pixel in the image are represented by an integer value or set of integer values. Tonal resolution is a measure of a scanner's resolution capability for small changes in intensity. Also called pixel depth or bit depth.
transfer function	The capability of a device to transmit frequencies. See also MTF.
transition	The portion of a signal between a first nominal state and a second nominal state.
transmittance	The fraction of the light that passes through an object.
transparency guide	A plastic template or form for holding and positioning transparencies on the scanner copyboard glass and for protecting the scanner calibration area.
tristimulus value	The amount of each of the three primaries red, green. and blue (R, G. and B) needed to match the color of the light on an object.
TWAIN	An industry-standard method for scanners and software to get scanned images into documents. If you are using a TWAIN-enabled scanner or software, you can usually "acquire" your scan directly from the software using a Scan button or command.
TXT Text-only format.	This format is useful for text if you do not need to retain the formatting.
U
unstack	To separate one or more pages from a stack and place them as individual items on the PaperPort software's Desktop.
V
visible light	The portion of the electromagnetic spectrum that the human eye can see.
W
white balance	The balancing of color components to create pure white when scanning a white object.
white point	The color that when scanned produces values of 255, 255, 255 in an 8-bit scanner. Ideally the white point is 100% neutral reflectance or transmittance. See also reflectance, transmittance.
WMF Windows Metafile format	This format is useful for black and white drawings that you want to use as scaleable clip art.
X
x-direction optical sampling rate	A scanner's sampling rate in the horizontal direction (across the page). The x-direction sampling rate is determined by the number of CCD elements in the CCD array. *See also y-direction sampling rate, optical sampling rate and sampling rate.*
Y
y-direction optical sampling rate	A scanner's sampling rate in the vertical direction (down the page). The y-direction sampling rate is determined by the mechanical motion of the scanner's carriage as it moves down the page. Some scanners vary the y-direction sampling rate in steps of lines pairs per inch (Lppi), offering more sampling rates to scale a document. Scanners with fixed, y-direction sampling rates offer fewer sampling rates or use interpolation, line dropping, or line replication to supply more sampling rates. *See also carriage, x-direction sampling rate, optical sampling rate and sampling rate.*
Z
zoom in	To make a page larger on the screen so you can see more detail.
zoom out	To make a page smaller on the screen so you can have a broader view of the page.

CompuServe™ is a U.S. trademark of CompuServe, Inc.
Microsoft® is a U.S. registered trademark of Microsoft Corp.
PaperPort™ is a trademark of Visioneer, Inc.in the United States and other countries.
Windows® and MS Windows® are U. S. registered trademarks of Microsoft Corp.