Panasonic AG-DVX100B Setup page 37

Coated Optics Is lens with a special coating to minimize the amount of light reflected back
to the lamp, and the amount of ambient light that mingles with the focused light leaving the
lens.
Codec Coder Decoder, a device used to encode a signal and decode it.
Color Bars A test signal that should be recorded at the beginning of every videotape. The
color bars test signal provides the necessary elements of a video signal that are added dur-
ing the initial set up of a tape machine.
Color Burst A few (8 to 10) cycles of 3.58MHz color sub carrier, which occur during the
back porch interval. Color burst amplitude is 40 IEEE units and phase is 180 degrees. The
color oscillator of a color television receiver is phase locked to the color burst.
Color Difference Signal The calculation of the chroma signal (R-Y, B-Y and G).
Color Phase The correct timing relationship within a color display - color is considered to
be in-phase when the hue is reproduced correctly.
Color Sub carrier The 3.58MHz signal which carries color information. This signal is super-
imposed on the luminance level. Amplitude of the color sub carrier represents saturation
and phase angle represents hue.
Color Temperature A measurement of overall color of a source of light, measured in de-
grees Kelvin (K). The higher the Kelvin reading the more blue the light, the lower the Kelvin
Temperature the redder the light. Normally, video uses lights that are 3200 Degrees Kelvin.
Component The normal interpretation of a component video signal is one in which the lumi-
nance and chrominance are sent as separate components, e.g. Analog components in MII
and Betacam VCRs, digital components UCRCB in CCIR re 601. RGB is, however, also a
component signal. Component video signals retain maximum bandwidth, unlike composite
systems.
Composite A composite video signal is one in which the luminance and chrominance infor-
mation have been combined using one of the coding standards: NTSC, PAL, SECAM, etc.
Composite Sync A signal consisting of horizontal sync pulses, vertical sync pulses, and
equalizing pulses only, with a no signal reference level.
Composite Video A mixed signal comprised of the luminance (black and white), chromi-
nance (color), blanking pulses, sync pulses and color burst.
Compression A process used to store digital information in a smaller block of space than it
would normally take
Compression Ratio This is the ratio of data in the original video picture signal to the
amount of data after compression.
Contrast The range of light and dark values in a picture or the ratio between the maximum
and the minimum brightness values. Low contrast is shown mainly as shades of gray, while
high contrast is shown as blacks and whites with very little gray. It is also a TV monitor ad-
justment, which increases or decreases the level of contrast of a televised picture.
Contrast Ratio A method of measuring the dynamic range of an image. A large contrast
ratio indicates that the projector works well despite extraneous light.
D
DATA Digital information stored or used by a computer
dB Decibel
dBm A measurement of sound, measurement made across 600 ohms.
DCT - Discrete Cosine Transformer is widely used to compress video; here 8x8 picture ele-
ments are converted to 8x8 frequency elements. This way the higher frequency numbers
can be minimized and compression made simpler.
DV Digital Video
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