Glossary of Video Terms and Acronyms - Isotest

Video Terms and Acronyms
Glossary
Crop – Term used for the action of moving left, right, top, and bottom
boundaries of a key.
Cropping – A digital process which removes areas of a picture (frame) by
replacing video pixels with opaque pixels of background colors. Cropping
may be used to eliminate unwanted picture areas such as edges or as
quasi-masking in preparation for keying.
Cross Color – Spurious signals resulting from high frequency luminance
information being interpreted as color information in decoding a composite
signal. Typical video examples are “rainbow” on venetian blinds and striped
shirts for example.
Cross Luminance – Spurious signals occurring in the Y channel as a
result of composite chroma signals being interpreted as luminance, such
as “dot crawl” or “busy edges” on colored areas.
Cross Modulation – See Chrominance-to-Luminance Intermodulation.
Cross-Assembler – Assembler that runs on a processor whose assembly
language is different from the language being assembled.
Cross-Color – An artifact observed in composite systems employing quadrature
modulation and frequency interleaving. Cross-color results from the
multiplicities of line-scan harmonics in the baseband signal, which provide
families of frequencies surrounding each of the main harmonic peaks.
These families become even more complex if there is movement in the
scene luminance signals between scans. Since the interstices are, therefore,
not completely empty, some of the information on the luminance signal
is subsequently decoded as color information. A typical visible effect is
a moiré pattern.
Crossfade – The audio equivalent of the video dissolve where one sound
track is gradually faded out while a second sound track simultaneously
replaces the original one. See Mix.
Crosshatch – A test pattern consisting of vertical and horizontal lines
used for converging color monitors and cameras.
Cross-Luminance – An artifact observed in composite systems employing
quadrature modulation and frequency interleaving. As the analog of crosscolor,
cross-luminance results in some of the information carried by the
chrominance signal (on color subcarrier) being subsequently interpreted as
fine detail luminance information. A typical visible effect is chroma crawl
and visible subcarrier.
Crossover Network – A device which divides a signal into two or more
frequency bands before low-frequency outputs of a crossover network. The
level of each output at this frequency is 3 dB down from the flat section of
the crossover’s frequency response curve.
Cross-Play – By cross-play capability is meant the ability to record and
reproduce on the same or a different machine; record at one speed and
reproduce at the same or a different speed; accomplish the foregoing
singly or in any combination without readjustment for tape or transport
type.
Crosspoint – a) The electronic circuit used to switch video, usually on a
bus. b) An electronic switch, usually controlled by a push-button on the
panel, or remotely by computer that allows video or audio to pass when the
switch is closed.
42 www.tektronix.com/video_audio
Cross-Sectional Modeling – This type of modeling is also a boundary
representation method available in PictureMaker. The artist can define an
object’s cross-section, and then extrude in the longitudinal direction after
selecting an outline to define the cross-section changes in scale as it traverses
the longitudinal axis.
Crosstalk – The interference between two audio or two video signals
caused by unwanted stray signals. a) In video, crosstalk between input
channels can be classified into two basic categories: luminance/sync
crosstalk; and color (chroma) crosstalk. When video crosstalk is too high,
ghost images from one source appear over the other. b) In audio, signal
leakage, typically between left and right channels or between different
inputs, can be caused by poor grounding connections or improperly shielded
cables. See Chrominance-to-Luminance Intermodulation.
Crosstalk Noise – The signal-to-crosstalk noise ratio is the ratio, in decibels,
of the nominal amplitude of the luminance signal (100 IRE units) to
the peak-to-peak amplitude of the interfering waveform.
CRT (Cathode Ray Tube) – There are three forms of display CRTs in color
television: tri-color (a color picture tube), monochrome (black and white),
and single color (red, green, or blue, used in projection television systems).
Many widescreen ATV schemes would require a different shape CRT, particularly
for direct-view systems.
CRT Terminal – Computer terminal using a CRT display and a keyboard,
usually connected to the computer by a serial link.
CSA – Common Scrambling Algorithm.
CSDI – See Compressed Serial Digital Interface.
CSELT (Centro Studi e Laboratori Telecomunicazioni S.p.A.) – CSELT
situated in Torino, Italy, is the research company owned by STET (Societa
Finanziaria Telefonica per Azioni), the largest telecommunications company
in Italy. CSELT has contributed to standards under ITU, ISO, and ETSI and
has participated in various research programs. In order to influence the
production of standards, CSELT participates in groups such as DAVIC, the
ATM Forum, and in the Network Management Forum.
CSG (Constructive Solid Geometry) – In CSG, solid objects are represented
as Boolean combinations (union, intersection, and difference) of
solids.
CSPS – Constrained System Parameter Stream.
CSS (Content Scrambling System) – A type of digital copy protection
sanctioned by the DVD forum.
CTA – Cordless Terminal Adapter.
Cue – a) An editing term meaning to bring all source and record VTRs to
the predetermined edit point plus pre-roll time. b) An audio mixer function
that allows the user to hear an audio source (usually through headphones)
without selecting that source for broadcast/recording; the audio counterpart
of a preview monitor. c) The act of rewinding and/or fast-forwarding a
video- or audiotape so that the desired section is ready for play.
Cue Control – A switch that temporarily disables a recorder’s Tape Lifters
during fast forward and rewind so the operator can judge what portion of
the recording is passing the heads.