DEFINITIONS OF TERMS (CONT.)
Field. One-half a television picture. One complete vertical scan
of the picture containing 262.5 lines. Two fields make up a
complete television picture (frame). The lines of Field 1 are
vertically interlaced with Field 2 for 525 lines of resolution.
Frame. A complete television picture, consisting of two fields.
See "Field".
Front Porch. Blanking level pulse at end of line of horizontal
scan, before horizontal sync pulse.
Horizontal Blanking Pedestal. That portion of each line of
composite video signal which blanks the picture while the CRT
retrace returns to the left side of the screen. Consists of front
porch, horizontal sync pulse, and back porch.
Horizontal Resolution. Smallest increment of a television
picture that can be discerned in the horizontal plane. This
increment is dependent upon the video bandwidth and is
measured in frequency. Horizontal resolution of a high quality
monochrome television receiver is 4.2MHz.
Horizontal Sync Pulse. Pulse at -40 IEEE units which
synchronizes horizontal scan rate of television receiver to
composite video signal. Starts each line at same horizontal
position.
Hue. Distinction between colors. Red, blue, green, yellow, etc.
are hues. White, black, and grey are not considered hues.
IFFE. Institute of Electrical and Electronic Engineers.
IEEE Unit. A standard 1-volt peak-to-peak composite video signal
is divided into 140 equal units, scaled from -40 to +100, which are
then called IEEE units. Luminance and chrominance amplitude are
measured in IEEE units. Sync pulses extend from 0 to -40 units.
Blanking level is 0. Picture information spans the +7.5 set-up level
(black) to + 100 (100% white) levels. Chroma amplitude is the peak-
to-peak amplitude of the color subcarrier, which rides on the
luminance level.
Interlace. Vertical offset between Field 1 and Field 2 that causes
lines of Field 1 to fall between the lines of Field 2. Also see "Field".
Luminance. The amount of light intensity perceived by the eye as
brightness. Luminance information is represented by the amplitude
of the composite video signal.
MATV. Master antenna television.
Monochrome. Black and white television signal. Contains sync
and luminance but no color burst or chroma.
NTSC. National Television Systems Committee. Established the
color television standards now in use in the U.S.A., and many other
nations of the world.
NTSC Color Bars. A pattern generated by the NTSC Generator,
consisting of eight equal width color bars. Colors are white (75%),
black (7.5% set-up level), 75% saturated pure colors red, green, and
blue, and 75% saturated hues of yellow, cyan, and magenta (mixtures
or two colors in 1:1 ratio without third color).
