H
HDMI (High-Definition Multimedia Interface): An all-digital
audio/video interface capable of transmitting uncompressed
streams
HDTV (High definition TV): A specific subset of the digital TV
standard that features increased horizontal and vertical resolution,
choice of interfaced or progressive scan, and widescreen images;
see enhanced-definition TV and standard-definition TV.
HDTV monitor: A TV set that can display full-resolution
widescreen high-definition images when connected to an outboard
HDTV tuner; see EDTV monitor.
HDTV set: An HDTV monitor that has a built-in high-definition
tuner.
HDTV tuner: An outboard, usually set-top, digital TV
tuner/decoder that can receive high-definition TV programs
broadcast over the air as well as from a satellite receiver or cable
service and then decode the signals for display in full resolution on
a widescreen HDTV monitor.
Home theatre system: A collection of audio and video
components designed and configured to reproduce something like
the picture and sound quality that would be experienced from a
movie in a good cinema. A home theatre is generally expected to
include a TV screen of reasonable size and a surround sound audio
system. See also Dolby Digital, Dolby Surround, Dolby Pro Logic,
and DTS.
Horizontal luminance resolution: Measured in lines, this is the
most common parameter for characterizing the reproduction of the
fine detail in video. (Do not confuse these “lines” with scan lines).
Hue: A color’s position in the visible spectrum from red to blue, or
its gradation of the tint; the professional name for a video
monitor’s tint control.
I
Interlaced scan: A video component or signal that assigns
alternating scan lines in a video frame to one of two fields, which
are then displayed separately (the opposite of progressive-scan).
Interlacing reduces picture flicker without the transmission of
additional video information.
L
LCD (liquid-crystal display): Color LCD panels are used in some
flat-screen TVs and computer monitors as well as in some video-
projection systems. Monochrome LCD readouts are used on the
faceplates of some A/V components and remote controls.
Letterboxing: The scaling of a widescreen image to fin within a
4:3 aspect ratio screen by shrinking the image’s vertical dimension
so that the width fits exactly and filling the resulting spaces above
and below the image with black bars. Critics of the technique think
that the screen area is being “wasted” by the letterboxing bars.
Line doubler: A devise that doubles the number of scan lines in a
video image, possibly in conjunction with progressive-scan
processing; line triplers and line quadruplers are also available.
Line interpolation: A process by which additional scan lines are
synthesized out of the original scan lines present in a video image;
used to increase the apparent vertical resolution; see line doubler.
Luminance (luma, Y): A video signal that encodes the point-to-
point brightness – not the overall brightness and not the color
(chrominance) – of a video image. Black-and-white TVs display
only luminance signals.
M
Macrovision: A set of alterations of a standard video signal
designed to prevent copying it or, failing that, to severely degrade
the quality of any copies made. DVD players usually apply two
types of Macrovision processing to their outputs, “Pseudo pulse”
and “color striping,” via circuitry enabled by instructions on the
disc.
MPEG (Moving Picture Experts Group): A committee of
engineers and scientists formed to issue standards for reduced-bit-
rate digital audio and video.
MPEG-2: The standard reduced-bit-rate, audio/video encoding
scheme for digital TV, DVDs and certain digital satellite
transmissions.
MPEG-4: A data-encoding standard incorporating advancements
to MPEG-2 and AAC in addition to facilities for the synthesis and
manipulation of audio and video “objects” (shapes, textures,
sounds, and so on).
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