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Tektronix provides test and measurement instruments, solutions and services for the computer, semiconductor, military/aerospace, consumer electronics and education industries worldwide.
The allocation of more bits to image areas of high activity which does not lend itself to all types of video compression techniques, especially when interframe sampling is used.
Industry:Entertainment
a) A compression technique that encodes the predictive residual instead of the original waveform signal so that the compression efficiency is improved by a predictive gain. Rather than transmitting PCM samples directly, the difference between the estimate of the next sample and the actual sample is transmitted. This difference is usually small and can thus be encoded in fewer bits than the sample itself.
b) Differential pulse code modulation that also uses adaptive quantizing; an audio coding algorithm which provides a modest degree of compression together with good quality.
c) A technique for compressing the transmission requirements of digital signals. ADPCM has been used by ABC between New York and Washington to allow NTSC transmission on a 45 Mbps (DS3) telephone company data transmission circuit.
d) A pulse code modulation system typically operating at a high sampling rate whereby coding is based on a prior knowledge of the signal to be processed (i.e., greater than, equal to, or less than the previous sample). The system is adaptive in that digital bits of code signify different sizes of signal change depending on the magnitude of the signal.
Industry:Entertainment
An ATV technique for improving detail of dark parts of the picture by increasing their level. If a complementary de-emphasis is performed at the receiver, noise can be reduced. Dolby B noise reduction (the form of Dolby noise reduction most common in consumer cassette recorders) is a classic example of complementary adaptive emphasis.
Industry:Entertainment
An algorithm developed by Fraunhofer Institut, AT&T, Thomas Brandt, and the CNET. The ASPEC algorithm was later used for developing the MPEG audio Layer 3 specification.
Industry:Entertainment
Either an aspect ratio twice as wide as it is high (18:9) or the field:frame ratio of interlaced scanning.
Industry:Entertainment
An algorithm that splits an audio signal into three non-uniform sub-bands.
Industry:Entertainment
4:1:1 indicates that Y' has been sampled at 13.5 MHz, while Cb and Cr were each sampled at 3.375 MHz. Thus, for every four samples of Y', there is one sample each of Cb and Cr.
Industry:Entertainment
A device that allows an ordinary NTSC television to receive pictures from a non-receiver-compatible ATV system.
Industry:Entertainment
A sampling system used to digitize the luminance and color difference components (Y, R-Y, B-Y) of a video signal. The four represents the 13.5 MHz sampling frequency of Y, while the R-Y and B-Y are sampled at 6.75 MHz – effectively between every other line only.
Industry:Entertainment
A feature of some waveform monitors which allows an internal 1-volt calibrator signal to be used as a reference for amplitude measurements.
Industry:Entertainment
