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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.
This method uses algebraic equations (usually polynomials) to define shapes and surfaces. The user can build and modify complex objects by combining and modifying simple algebraic primitive shapes.
Industry:Software
Also called thermal noise, a transmission or recording impairment that manifests itself as snow in a picture and hiss in sound. A number of techniques have been developed to reduce random noise in a picture through signal averaging.
Industry:Software
Fast rise time square waves cannot be used for testing bandwidth-limited systems because attenuation and phase shift of out-of-band components will cause ringing in the output pulse. These outof- band distortions can obscure the in-band distortions that are of interest.
Sine-squared pulses are bandwidth limited and are useful for testing bandwidth- limited television systems. ‘’’Description of the Pulse:’’’ Sine-squared pulses look like one cycle of a sine wave as shown. Mathematically, a sinesquared wave is obtained by squaring a half-cycle of a sine wave.
Physically, the pulse is generated by passing an impulse through a sinesquared shaping filter.
‘’’T Intervals:’’’ Sine-squared pulses are specified in terms of half amplitude duration (HAD) which is the pulse width measured at the 50% pulse amplitude points. Pulses with HADs which are multiples of the time interval T are used to test bandwidth limited systems. T, 2T, and 12.5T pulses are common examples. T is the Nyquist interval, or 1/2 fc where fc is the cutoff frequency of the system to be measured. For NTSC, fc is taken to be 4 MHz, thus T is 125 nsec.
‘’’T Steps:’’’ The rise times of transitions to a constant luminance level (such as the white bar) are also specified in terms of T. A T step has a 10% to 90% rise time of nominally 125 nsec, while a 2T step has a rise time of 250 nsec. Refer to the figure below.
‘’’Energy Distribution:’’’ Sine-squared pulses possess negligible energy at frequencies above f = 1/HAD. The amplitude of the envelope of the frequency spectrum at 1/(2 HAD) is one-half of the amplitude at zero frequency.
Industry:Software
Texture mapping is made possible by full color mode.
Texture mapping refers to the process of covering the surface of a polygon with values what come from a “texture” that come from some picture stored elsewhere in the system, say a scanned in image.
Industry:Software
The piece of hardware within the chassis that directs power from an electrical outlet to the chassis, the monitor, and other internal devices.
Industry:Software
In a digital video system, the number of pixels corresponding to the reference picture width. Some pixels at the borders of the picture region may be corrupted by the picture blanking transitions and by the effects of post-production image processing. Currently, SMPTE 260M defines a clean aperture within the production aperture, confining visible artifacts around the image to a thin border.
Industry:Software
A scheme for sampling at a frequency lower than that prescribed by the Nyquist sampling theorem.
Industry:Software
A mechanism that allows control over what viewers may see depending on the settings in the DVD player, the parental code on a DVD, and the structure of the material on the DVD. This is especially useful for youthful viewers whose parents wish to exercise a degree of control over what their children can watch.
Industry:Software
