|
Dictionary of Technical Terms - I
A B
C D E F G
H I J K L M
N O P Q R
S T U V W
X Y Z
Num
I
I
A designator used to name one of the color
components of the NTSC video signal. The formula for deriving I
from red, green, and blue is .60R - .28G -.32B. The term I also
designates an M-Format color component.
IC
Integrated circuit.
icon
In desktop computing and editing, a graphic symbol
that represents a file, a tool, or a function.
ID
Identification.
idling current
The current drawn by a circuit, such as an
amplifier, when no signal is present at its input.
IMD
See intermodulation distortion.
impedance
The total of the resistive and reactive opposition,
measured in ohms, that a circuit presents to the flow of
alternating current at a given frequency.
inbetweening (key frame interpolation)
Given two or more key frames, inbetweening is the
act of generating the intermediate field rate information to cause
the image to change from one key frame to the next.
inch
Unit of measure of length. One inch equals one
twelfth of a foot or 25.4 millimeters.
index of refraction
The ratio of the velocity of light in a vacuum to
the velocity of light in a given medium.
init page
A menu for setting the proper editing system
operating conditions at the start of an edit session.
injection laser
A solid state semiconductor device consisting of at
least one p-n junction capable of emitting coherent or stimulated
radiation under specified conditions. The device incorporates a
resonant optical cavity.
in-point
The beginning of an edit; the first frame that is
recorded.
input return loss
See return loss.
input selector
A routing switcher or auxiliary bus used to expand
the number of video or key inputs that can feed an input of a
digital picture manipulator or keyer. Many keyers only accept one
key source and fill, but by connecting an input selector to those
inputs, many more source and fill signals become available just by
selecting crosspoints on the input selector.
input-looping
A device's input loops back out so that the incoming
signal can be sent elsewhere.
insert
A key fill signal.
insert edit (insert mode)
An edit mode in which the time code and control
track already existing on the record tape are not replaced during
the editing process. The system edits using the pre-recorded
control track and time code.
insert event
A GVG editor command that takes an edit in the Mark
Table and puts it into the Edit Decision List just after the line
being pointed to.
insertion loss
Signal loss within a circuit. Usually expressed in
decibels as the ratio of input power to output power.
integrated circuit
An electronic device in which both active and
passive circuits are contained in a single miniature multi-pin
package.
intensity modulation (IM)
Used in fiber optics as a method of transmission in
which the analog signal directly modulates the light source.
interface
Device or circuit used to interconnect two pieces of
equipment.
interlaced
Short for interlaced scanning. Also called line
interlace. A system of video scanning whereby the odd- and
even-numbered lines of a picture are transmitted consecutively as
two separate interleaved fields.
intermodal dispersion
A difference in propagation time of photons
traveling on different paths in an optical fiber.
intermodulation distortion (IMD)
Distortion that results when two or more pure tones
produce new tones with frequencies representing the sum and/or
difference of the original tones and their harmonics.
interpolation
In digital video, the creation of new pixels in the
image by some method of averaging the values of neighboring pixels.
This is necessary when an image is digitally altered, such as when
the image is expanded or compressed.
in-time
The time of edit start.
I/O
Input/output. Typically refers to sending
information or data signals to and from devices.
IP
Information provider.
IRE (Institute of Radio Engineers)
Units of measurement dividing the area from the
bottom of sync to peak white level into 140 equal units.
One-hundred-forty IRE equals 1 volt peak-to-peak. The range of
active video is 100 IRE.
ISDN
Integrated Services Digital Network.
iso
In videotaping, to record the output of each camera
in a multiple-camera shoot on its own separate VTR.
ISO
International Standardization Organization.
isophasing amplifier
A timing device that corrects for small timing
errors.
ITU
International Telecommunications Union. An
international broadcast standards committee that replaced the
CCIR.
ITU-R BT.601-2
Formerly known as CCIR 601. An international
standard for component digital television from which was derived
SMPTE 125M (was RP-125) and EBU 3246E standards. This International
Telecommunications Union (ITU) recommendation defines the sampling
systems, matrix values, and filter characteristics for both Y, B-Y,
R-Y and RGB component digital television.
ITU-R BT.656
Formerly known as CCIR 656. The physical parallel
and serial interconnect scheme for ITU-R BT.601-2 (CCIR 601). ITU-R
BT.656 defines the parallel connector pinouts as well as the
blanking, sync, and multiplexing schemes used in both parallel and
serial interfaces. Reflects definitions in EBU Tech 3267 (for 625
line signals) and in SMPTE 125M (parallel 525) and SMPTE 259M
(serial 525).
IXC
Interexchange carrier.
A B
C D E F G
H I J K L M
N O P Q R
S T U V W
X Y Z
Num
|