24-bit color
24-bit color images are composed of three 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.
36-bit color
36-bit color images have 3 color channels of 12 bits each - - red, green and
blue. When combined, the red, green and blue channels provide up to more than 1 billion
colors.
8-bit grayscale
Images containing 256 possible shades of gray.
Address
A number that identifies the I/O location of the device at the host computer.
Alpha channel
An 8-bit channel reserved by some image-processing applications for masking
additional color information.
Analog
Continuously variable signals or data. Description of the continuous wave or signal
(such as the human voice) using an electrical voltage variation. Used for voice, visual,
and computer data communication. The digital or pulse output of a computer or terminal
must be converted to an analog signal before it can be transmitted over analog grade lines
Anti-aliasing
The rendering of hard-edged objects so that they blend smoothly into the background. A
technique for merging object-oriented art into bitmaps.
Application Software
General term for software packages. Scanner-related application software usually refers
to the software for editing, drawing and optical character recognition (OCR).
ASCII (American Standard Code for Information Interchange)
Standard by which many computers assign code numbers to letters, numbers and symbols.
Used for text exchange between computer platforms.
Aspect Ratio
The ratio of horizontal to vertical units
Automatic Configuration
A MiraPhoto driver feature that automatically finds the available I/O address
Automatic Exposure
A MiraPhoto driver feature that automatically sets the suitable brightness and contrast
for the user.
Automatic Preview
A MiraPhoto driver feature that automatically previews images instantly whenever
brought up.
Banding
A visible stair-stepping of shades in a gradient.
Bit
A unit that can hold information with the changes between 0 and 1.
Bit depth
The number or bits of each pixel in an image, determining its color or tonal
range
Bitmap
An image formed by rectangular grid of picture elements (pixels). The computer assigns
a value to each pixel, from one bit of information (indicating black or white) to 24 bits
per pixel (for full-color computer displays), to as many as 64 bits per pixel for some
types of full-color images. A bitmap is an image defined by a collection of dots, as
opposed to a vector image, which is defined by mathematical formulas.
Brightness
A measurement of image intensity
Byte
A unit that contains 8 bits representing values 0 to 255.
Calibration
A process that extracts some runtime dynamic information from devices
CCD
A charge-coupled device, or CCD, is a light sensitive electronic device that converts
light into an electrical charge.
CMYK (Cyan, Magenta, Yellow, Black)
The subtractive primaries, or process colors, used in color printing. Black (K) is
usually added to enhance color and to print a true black.
Color channel
Different color channels combines color images on the computer . RGB, the most
commonly used color model, has the three channels of red, green and blue.
Color Match
Match the color between source device and destination device.
Color separation
The division of an image into its component colors for printing. Each color separation
is a piece of negative or positive film.
Compression
Encoding the bits of information in an image file so that it takes up less space when
stored. Compression results in little or no distortion.
Continuous-tone
Complete range of tones from black to white such as photographs, paintings and
drawings. Negatives or positives with a broad range of tones that have no screened dots.
Contrast
The difference of the light from dark areas in an image. The more the difference, the
greater the contrast.
Data compression
"Squeezing" data for transferring data efficiently . Portions of the
data are removed by an algorithm that will restore the data when needed.
DCS
Desktop color separation is an image format consisting of four separate CMYK PostScript
files at full-resolution and of an EPS,a format-controllong file.
Decompression
The expansion of compressed image files. See also lossy and lossless.
Default
Commands or parameters that take effect if no other option is specified.
Density
The ability of a material to absorb light. Measurement of the light transmission of a
transparent or translucent object or the light-absorbency of a reflective surface. In
photography, measurement of the opacity of a transparent or translucent object. On a film
negative, the greater the density area, the more black or more developed it is. Density is
measured from 0 to 4.0. It is calculated by measuring the reflectance or transmittance of
light and calculating theoretical light absorption.
Descreen
Removal of dot patterns during or after scanning printed material by defocusing the
image. This avoids moire patterning and color shifts during subsequent reprinting. The
Descreen filter is used for the image printed out by dithering. Without the Descreen
filter process, the scanned dithering image will have a moire effect.
Dialog Box
A window that allows users to make options, enter data and receive messages
Digital ICE
Digital ICE (Image Correction and Enhancement) is a patented artifact-elimination technology developed by ASF (Applied Science Fiction. It is used to automatically remove scratches, fingerprints and dust from film surfaces during the scanning process and thus provide a clean, distortion-free and high-quality scanned image.
Dither
A technique that uses dispersed dots to simulate gray shades so that an image looks
like a greyscale one.
Dot
The smallest and visible point that can be displayed on a surface.
DPI
An acronym for dot per inch. A measurement of resolution.
Driver
A program functioning as a bridge between application software and hardware. It usually
encapsulates the hardware details to provide easier interface for the application
software.
Drum scanner
An optical input device(scanner) that mounts reflective or transparent input media on a
revolving cylinder for digitizing.
EPS (Encapsulated PostScript)
An only format that carries a pict preview and supports saving and transferring line
screen data . In bitmapped mode, it also supports transparent whites.
Export
To output data in a form that another program can read.
File
A name of information collection stored as an apparent unit on a secondary
storage medium such as a disk drive.
Film
Photosensitive material, generally on a transparent base, which will receive character
images, and can be chemically processed to expose those images. In image setting, any
photosensitive material, transparent or not, may be called film.
Film negative
A kind of film with a reversed image, in which dark areas appear white, and vice versa.
Gamma
A mathematical function used to describe the relationship between input densities
(levels) and output densities (levels.) The measurement of how compressed or expanded dark
or light shades become in an image.
Gamma Correction
An operation used to correct data that is not really reproduced by some devices. In
order to make the correction, the characteristic of the output device (i.e., gamma value)
must be known.
Gradation
A smooth color transition from black to white, colorful to colorless, or one color to
another.
Gray balance
The balance between CMYK colorants required to produce neutral grays without a color
cast.
Gray levels
Discrete tonal steps in a continuous tone image, inherent to digital data. Most CT
images will contain 256 gray levels per color.
Grayscale
A range of intensity (i.e., gray shade) for a color plane.
Highlight
The brightest intensity for an image
Histogram
A graphic representation of the number of pixels with given color values, showing the
breakdown or distribution of color values in a picture.
Hue
The wavelength of light of a color in its purest state (without the addition of white
or black).
Image Type
The image type used to represent a document. It affects how information is saved and
how original documents can be reproduced.
Input
Enter raw data, text, graphics, imagery or commands in a computer.
Interpolation
The process of increasing the resolution of an image by adding new pixels
throughout the image, the colors of which are based on neighboring pixels.
Interface Cable
A cable connecting the scanner with a host computer. In a PC system, it connects to the
PC through the SCSI interface card.
Interface Card
An I/O (input/output) card in the host computer expansion slot. It connects a scanner
with a host computer.
Interpolation
An operation performed by the driver. It generates a new and higher resolution
image from a lower resolution image by applying an appropriate algorithm.
Inverse Image
A MiraPhoto driver feature that negates the grayscale value of each pixel in an image.
JPEG (Joint Photographic Expert Group)
An image compression/decompression standard that divides the image into cells which are
condensed based on content analysis.
Line Art
A graph or image containing only lines, text and drawings
Lossless
Data compression algorithms that store data in a more efficient format and causes no
data loss in the compression process. Typically this type of compression has a ratio
up to 8:1.
Lossy
Data compression algorithms that eliminate some of the image data without
affecting the perceived image quality. Typically this type of compression has ratios from
10:1 to 100:1.
LPI (Lines Per Inch)
A printing term for the frequency of lines on a screen (usually ranging from
55-200). LPI refers to the frequency of the horizontal and vertical lines.
Luminosity
A variable corresponding to the brightness of color.
LZW
The Lempel-Ziv-Welch image compression technique.
Mirror Image
A MiraPhoto driver feature that flips an image left and right
Moire Pattern
An interference pattern usually unexpected and annoying
Monitor calibration
The process of optimizing the color settings of a monitor to match selected output
colors of a printer.
Monochrome
Black-and-white or Single-colored grayscale images .
Neutral gray
Any level of optical density (from white to black)without apparent hue consisting of
equal levels of red, green, and blue (RGB).
Noise
Incorrect reading of pixel values normally due to electrical interference or device
instability during scanning .
Non-lossy
Image compression without loss of quality.
Non-Uniform Resolution
A MiraPhoto driver feature that allows horizontal and vertical resolution to be
different
Non-Uniform Scaling
A MiraPhoto driver feature that allows horizontal and vertical scaling to be different.
Optical resolution
In a scanning context, this refers to the number of truly separated readings taken from
an original within a given distance, as opposed to the subsequent increase in resolution
(but not detail) created by software interpolation.
Original
A term referred to any artwork or photograph to be scanned.
Output
A process of sending computer results to a CRT or printer.
PICT / PICT2
A common format for defining bitmapped or object-oriented images on the Macintosh. The
more recent format (PICT2) supports 24-bit color.
Pixel
The smallest picture element unit in an image
PostScript
The standard device-independent language developed by Adobe Systems that describes the
appearance of pages in documents. PostScript is the final storage format of pages ready
for printing out. Encapsulated PostScript describes a graphic, image or complete page in a
final form that can be exchanged between application programs. Under such circumstances a
PostScript-described item can be included in another layout.
PPI (Pixels Per Inch)
A unit for measurement of scanning resolution. The better the optics of a scanner, the
higher thePPI. PPI is equivalent to DPI.
Preview
An operation that gets a rough image of a document for setting parameters and analysing
image conveniently .
Preview Size
The size of the preview window area.
RAM (Random Access Memory)
A kind of memory in a computer which data can be read from and entered into,but
all data in the memory will be lost once the power is shut off. RAM may be expanded by
adding memory chips or memory boards.
RGB (Red, Green and Blue)
The color model in which color images are composed of red, green and blue color
channels. Most computer displays and image editing programs use the RGB color model.
Resolution
The measurement of image details. The smallest discernible detail in visual rendering.
Resolution may be stated in terms of spot diameter, line width, pixel matrix dimension,
raster lines or dots/inch.
Sampling
The process of converting analog data into digital data by taking a series of samples
or readings at equal time intervals.
Saturation
The amount of gray in a color. The higher the gray content, the lower the saturation.
Scaling
An operation that enlarges or shrinks an image
SCSI
An acronym for Small Computer System Interface. It provides an interface for the
computer system with device independence within a class of devices.
SCSI ID
A number for a device on the SCSI bus chain ranging from 0 to 7. This number represents
the device when it is communicating on the SCSI bus.
Shadow
The darkest intensity of an image
Sharpen
Electronic photo-retouching function for enhancing image detail and contrast either
globally or in selected regions of the picture.
Sheetfed
A type of scanning device in which the original is moved past the scanning head, rather
than having the scanner head moved. Usually appropriate only for sheets of paper.
Single-bit images
Black and white bitmapped images or line art image type.
TGA (Targa)
A file format for exchanging 24-bit color files on PCs.
Threshold
A value for text data type. Pixel value above the threshold value is represented
by 1 (i.e., white) while pixel value below the threshold value is 0 (i.e., black).
TIFF (Tag Image File Format)
A popular image file format. It contains several effective compression schemes which
save space for data storage
Tone curves
Also known as gamma curves. These are used to adjust the overall tonal range of
an image or the individual tonal ranges of each color channel.
TWAIN
A standard software protocol and API (Application Programming Interface) for
communication between application software and image acquisition devices
TWAIN-Compliant
A term that identifies application software or devices that follow the TWAIN standard.
Zoom
A MiraPhoto driver feature allowing users to see more details of the document.
Users can zoom-in on the scan area repeatedly.