Acronyms/Nomenclature
59
Luminance:
the black-and-white component of a video signal, abbreviated Y. Luminance is combined
with the color signal (chrominance) in composite video connections, but kept apart in S-Video and
component connections.
Noise:
random, unwanted interference with signal, resulting in “snow,” random flecks, or specks of
unwanted color.
NTSC (National Television Standards Committee):
color video signal that uses 525 scan lines with
30 frames/60 fields per second. All United States broadcasting uses the NTSC standard.
Overlay:
keyed insertion of one image into another. Overlay is used, for example, to superimpose
computer-generated text on top of a video image. In video, overlay requires synchronized sources for
proper operation.
PAL (Phase Alternating Line):
A color TV standard developed in Germany that broadcasts 25
interlaced frames per second (50 half frames per second) at 625 lines of resolution. Brazil uses PAL M,
which broadcasts 30 fps. PAL is used throughout Europe and China as well as in various African,
South American and Middle Eastern countries. PAL's color signals are maintained automatically.
PLUGE (Picture Line-Up Generation Equipment):
Used for aligning monitors and other video
devices. In some versions of color bars, PLUGE is the black set at the bottom of the red bar that
contains bars that are blacker-than-black, black, and whiter-than-black. Users adjust monitor
brightness by watching the PLUGE so the whiter-than-black bar is just visible, and both the black and
blacker-than-black bars are no longer distinct.
Progressive scanning:
the opposite of interlaced scanning. Progressive scanning shows each scanning
line in sequence for a more seamless, film-like image.
Saturation:
the color intensity of an image. An image high in saturation appears very bright. An
image low in saturation appears duller and more neutral. A 100-percent saturated color does not
contain any white; adding white reduces saturation. An image without any saturation is also referred
to as a grayscale image.
SDI (Serial Digital Interface):
a digital video interface used with broadcast-grade video.
SECAM (Système Electronique Couleur Avec Memoire):
A color TV standard from France that
broadcasts 25 interlaced frames per second (50 half frames per second) at 625 lines of resolution, 576
of which are the visual frame. Used in France and Russia and other countries in Africa, Eastern
Europe and the Middle East, several countries have switched from SECAM to PAL, and production
equipment for SECAM is no longer made. Today, almost all work is done in component video
systems that support 576 scanning lines (SECAM and PAL) or composite video (PAL) and converted
to SECAM for transmission.
SMPTE (Society of Motion Picture & Television Engineers) Bars:
a multi-purpose test pattern used
as an adjustment reference and a verification of correct video display operation.