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- Number of terms: 20560
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- Company Profile:
Tektronix provides test and measurement instruments, solutions and services for the computer, semiconductor, military/aerospace, consumer electronics and education industries worldwide.
Maximum rate of transmitting pulse signals through a channel of given bandwidth. If B is the effective bandwidth in Hertz, then 2B is the maximum number of code elements per second that can be received with certainty. The definition is often inverted, in effect, to read “the theoretical minimum rate at which an analogue signal can be sampled for transmitting digitally.” Nyquist Rule
Industry:Software
Distortions which are independent of signal amplitude.
These distortions occur as a result of the system’s inability to uniformly transfer amplitude and phase characteristics at all frequencies.
When fast signal components such as transitions and high frequency chrominance are affected differently than slower line-rate or field-rate information, linear distortions are probably present. These distortions are more commonly caused by imperfect transfer characteristics in the signal path. However linear distortions can also be externally introduced. Signals such as power-line hum can couple into the video signal and manifest themselves as distortions.
Industry:Software
A major shift in the quality of a television picture in the presence of motion that is so jarring to the viewer that the system might actually appear better if it had continuously lower quality, rather than jumping from high-quality static image to a lower quality dynamic one.
Industry:Software
Display system in which two interleaved fields are used to create one frame. The number of field lines is one-half of the number of frame lines. NTSC (M) systems have 262.5 lines per field. PAL (B, D, G, H, I) scan system have 312.5 lines per field. Each field is drawn on the screen consecutively, first one field, then the other. The field scanned first is called the odd field, the field scanned second is called the even field. The interlaced scanning system is used to prevent screen flicker. If frames were scanned on the screen without interlacing fields, the light level created by the first frame would decrease noticeably before the next frame could be scanned. Interlacing the fields allows the light level of the screen to be held more constant and thus prevent flicker.
Industry:Software
With a few exceptions, magnetic tape consists of a base film coated with magnetic particles held in a binder. The magnetic particles are usually of a circular shape and approach single domain size. See Gamma Ferric Oxide, Chromium Dioxide, and Cobalt Doped Oxide.
Industry:Software
Intervals between successive samples must be equal to or less than one-half the period of highest frequency.
Industry:Software
A) A term given to a key which contains soft edges and information at many different luminance levels. This is the ability of the keyer to key many levels linearly and means the keyer has a gain close to one. b) A process for the selective overlay of one video image upon another, as through chroma key. Control of the ratio of foreground to background is determined by the specifications derived from luminance information, and provided in the linear key data. Ratios to be applied are carried for each picture element in the alpha channel. The process permits realistic rendering of semi-transparent objects.
Industry:Software
A) A two-dimensional vector used for motion compensation that provides an offset from the coordinate position in the current picture to the coordinates in a reference picture. b) A pair of numbers which represent the vertical and horizontal displacement of a region of a reference picture for production.
Industry:Software
A television subcarrier at a frequency that is an odd multiple of one half the line rate (for example, the NTSC colour subcarrier).
Such subcarriers fall onto a line in the spatio-temporal spectrum that is simultaneously high in vertical detail and in temporal detail, and is therefore not likely to be objectionably visible under normal viewing conditions.
Industry:Software
