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- Number of terms: 20560
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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.
A European video standard with image format 4:3, 625 lines, 50 Hz and 6 Mhz video bandwidth with a total 8 Mhz of video channel width.
Industry:Entertainment
A device designed to generate special effects. The simplest devices process a single video signal, change its color, generate sepia tones, invert the picture to a negative, posterize the image and fade or break up the image into various patterns. More sophisticated equipment uses several video sources, computer-generated graphics and sophisticated animation with digital effects.
Industry:Entertainment
An instrument with which a photographic emulsion is given a graduated series of exposures to light of controlled spectral quality, intensity, and duration. Depending upon whether the exposures vary in brightness or duration, the instrument may be called an intensity scale or a time scale sensitometer.
Industry:Entertainment
Long, highly directional microphone designed to pick up sounds directly in front of the microphone, rejecting sound from other directions. Named for its appearance.
Industry:Entertainment
The ratio in decibels (dB), of an audio or video signal, between the signal's maximum peak-to-peak signal voltage and the measured voltage of what remains when the signal is removed, (i.e., the ratio of the signal to that of the noise). In video, the higher the ratio, the less snow is visible. In audio, the higher the ratio, the cleaner the sound. Audio s/n ratios vary tremendously from compact discs/camcorder AFM Hi-Fi tracks (typically 90 dB) to VCR linear tracks (typically 40 dB).
Industry:Entertainment
There is an SMPTE time code standard (hr:min:sec:frame) used to identify video frames.
Industry:Entertainment
A compact videocassette record/playback tape format which uses eight millimeter wide magnetic tape. A worldwide standard established in 1983 allowing high quality video and audio recording. Flexibility, lightweight cameras, and reduced tape storage requirements are among the format’s advantages.
Industry:Entertainment
Sub-band coding for images has roots in work done in the 1950s by Bedford and on Mixed Highs image compression done by Kretzmer in 1954. Schreiber and Buckley explored general two channel coding of still pictures where the low spatial frequency channel was coarsely sampled and finely quantized and the high spatial frequency channel was finely sampled and coarsely quantized. More recently, Karlsson and Vetterli have extended this to multiple subbands. Adelson et al. have shown how a recursive subdivision called a pyramid decomposition can be used both for compression and other useful image processing tasks. A pure sub-band coder performs a set of filtering operations on an image to divide it into spectral components. Usually, the result of the analysis phase is a set of sub-images, each of which represents some region in spatial or spatio-temporal frequency space. For example, in a still image, there might be a small sub-image that represents the low-frequency components of the input picture that is directly viewable as either a minified or blurred copy of the original. To this are added successively higher spectral bands that contain the edge information necessary to reproduce the original sharpness of the original at successively larger scales. As with DCT coder, to which it is related, much of the image energy is concentrated in the lowest frequency band. For equal visual quality, each band need not be represented with the same signal-to-noise ratio; this is the basis for sub-band coder compression. In many coders, some bands are eliminated entirely, and others are often compressed with a vector or lattice quantizer. Succeedingly higher frequency bands are more coarsely quantized, analogous to the truncation of the high frequency coefficients of the DCT. A sub-band decomposition can be the intraframe coder in a predictive loop, thus minimizing the basic distinctions between DCT-based hybrid coders and their alternatives.
Industry:Entertainment
Data compression software that continually analyzes and compensates its algorithm, depending on the type and content of the data and the storage medium.
Industry:Entertainment
A compression system which requires equal processing capability for Compression and decompression of an image. This form of compression is used in applications where both compression and decompression will be utilized frequently. Examples include: still-image databasing, still-image transmission (color fax), video production, video mail, videophones, and videoconferencing.
Industry:Entertainment
