Epson Perfection 640U Reference Manual page 118

port
An interface channel through which data is transmitted between devices.
primary colors
Basic colors. See additive primary colors and subtractive primary colors.
resolution
Indication of how finely an image is resolved into pixels. Can be measured in
dots per inch (dpi), pixels per inch (ppi), or samples per inch (spi).
scan
An operation performed by the sensor and the carriage. The image is divided
into pixels by scanning.
scanning area
The physical size of the image that can be scanned by the scanner.
sRGB
A standard color space used as the default color space within the Windows 98
color management system (ICM 2.0).
subtractive primary colors
The colors of cyan, magenta, and yellow (CMY) which produce black when mixed
in certain amounts. In printing, black is often added to give more definition as
mixing of actual inks cannot produce pure black.
threshold
A reference point that is used to determine whether data will be processed as
"on" or "off". In the case of color image data, "on" means that a certain color will
appear in a pixel or dot, and "off" means that color will not appear there.
tone correction
A method of adjusting the tone curve so that the reproduction results on different
types of output devices have gradations similar to the original image.
tone curve
The graph that shows the contrast ratio between the input (original image) and
output (image data) in image processing.
unsharp mask
Originally a photographic process in which a sharply focussed and a slightly out-
of-focus image are combined to produce a sharper image. This process is
simulated by software to produce the same effect.
USB
A Universal Serial Bus. A hardware interface for connecting low-speed
peripherals such as a keyboard, mouse, scanner, or printer to the computer.
USB hub
A device that normally provides four TYPE A sockets to increase the number of
USB ports on a PC.
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Glossary