Raster: The area of a video display that is covered by sweeping the
electron beam of the display in a series of horizontal lines from
upper left to lower right (from the viewer’s perspective).
Redundancy: This trait of images is exploited by compression
algorithms. Superfluous information can be eliminated during
compression and restored without loss during decompression.
Resolution: The number of pixels that can be displayed on the
monitor horizontally and vertically. The higher the resolution, the
more details can be displayed. Pixel
RGB: Red, Green and Blue: the primary colors in additive color
mixing. RGB designates the method used in computer technology of
encoding image information in pixels, each containing some
combination of the three primaries.
ROM: Read Only Memory: Memory storage that, having been
programmed once, retains its data without requiring electrical power.
EPROM
Run Length Encoding (RLE): A technique used in many image
compression methods, including JPEG. Repeating values are not
stored separately but with a counter to indicate how many times the
value occurs in succession – the length of the “run”.
Scaling: Adaptation of an image to a desired size.
SCSI: Small Computers System Interface. SCSI was long preferred
as the hard drive interface for some high-performance PCs because
of its high data rate. Up to eight SCSI devices can be connected to a
computer at the same time.
SECAM: “Séquentiel Couleur à Mémoire”, a color TV transmission
system used in France and Eastern Europe. Like PAL, SECAM
video has 625 lines per frame and 50 image fields per second.
NTSC, PAL
Serial port: Data transmitted via a serial port is processed one
bit at a time; that is, “serially” – one after another. The
transmission rate is much slower than that of a parallel port, where
parallel data lines allow multiple bits to be sent simultaneously.
Serial ports are named “COMn”, where n is a number (e.g.
“COM2”). Parallel port
