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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 video signal that represents an infinite number of smooth gradations between given video levels. Analog video whether transmitted over cables, read from videotapes or broadcast, is subject to degradation due to noise, distortion and other electronic phenomena. Normal signal levels should be within 0.7-1 volt. By contrast, a digital video signal assigns a finite set of levels.
Industry:Entertainment
A device for displaying large, readable text on a partially transparent screen for video production. The tele-prompter uses a monitor mounted under the camera lens, facing up, and a mirrored glass which reflects the monitor's image toward the talent. Since the camera shoots through the mirrored glass and the mirrored glass is transparent to the camera, the talent can look directly into the camera lens as they read the script from the glass.
Industry:Entertainment
The process of reducing aliasing effects. Aliasing occurs because a raster system is “discrete,” i.e., made up of pixels that have finite size. Representing a line with black and white pixels results in “jaggies,” or “aliases.” These are particularly disturbing during animation. To correct them, “anti-aliasing” techniques are used. These tech AM-VSB (Amplitude Modulation with Vestigial Sideband) – The form of modulation used in broadcast and cable television transmission. It is more efficient than dual-sideband amplitude modulation and is easier to implement than single-sideband amplitude modulation.
Industry:Entertainment
Trellis coding is a source coding technique that has resulted in numerous publications and some very effective source codes. Unfortunately, the computational burden of these codes is tremendous and grows exponentially with the encoding rate. A trellis is a transition diagram, that takes time into account, for a finite state machine. Populating a trellis means specifying output symbols for each branch, specifying an initial state yields a set of allowable output sequences. A trellis coder is defined as follows: given a trellis populated with symbols from an output alphabet and an input sequence x of length n, a trellis coder outputs the sequence of bits corresponding to the output sequence x that maximizes the SNR of the encoding.
Industry:Entertainment
a) An adjustable opening in a lens which, like the iris in the human eye, controls the amount of light entering a camera. The size of the aperture is controlled by the iris adjustment and is measured in f-stops. A smaller f-stop number corresponds to a larger opening that passes more light.
b) As applied to ATV, the finite size and shape of the point of the electron beam in a camera or picture tube. As the beam does not come to an infinitesimal point, it affects the area around it, reducing resolution.
Industry:Entertainment
A camera which contains an electronic image sensor rather than photographic film. The lens focuses an image on an electronic tube or CCD chip. A camera has electronic circuitry which generates color and sync pulses. Most portable consumer cameras are equipped with a full complement of audio circuitry, e.g., microphone, audio amplifier and additional audio electronics. In order to obtain better quality images, a professional camera has three tubes or a triple CCD system, one for each basic color. Most professional cameras have a genlock input, which allows the camera to be synchronized to an external source. Some cameras also include basic character generators for titling purposes.
Industry:Entertainment
Perhaps the major drawback to each of the Huffman encoding techniques is their poor performance when processing texts where one symbol has a probability of occurrence approaching unity.
Although the entropy associated with such symbols is extremely low, each symbol must still be encoded as a discrete value. Arithmetic coding removes this restriction by representing messages as intervals of the real numbers between 0 and 1. Initially, the range of values for coding a text is the entire interval (0, 1). As encoding proceeds, this range narrows while the number of bits required to represent it expands. Frequently occurring characters reduce the range less than characters occurring infrequently, and thus add fewer bits to the length of an encoded message.
Industry:Entertainment
A procedure for combining selected portions of video footage in order to create a new, combined version. A variety of editing consoles are available. During video editing, special effects such as wipes, dissolves, inserts, etc. can be added. Professional editing is done using time code recorded on every frame of the magnetic tape allowing single frame accuracy. Audio editing is often carried out simultaneously with video editing.
Industry:Entertainment
The ratio of the width of the picture to the height. For most current TVs, this ratio is 4:3. For HDTV, the ratio will be 16:9. The aspect ratio, along with the number of vertical scan lines that make up the image, determines what sample rate should be used to digitize the video signal.
: 1:9 Description 1.0 9 Square photographic formats, including Instamatic 126 1.33 12 Existing television, old movies, Pocket Instamatic 110 1.44 13 IMAX film 1.5 13.5 35mm still photographs, proposed for theatrical release 1.61 14.5 Faroudja HDTV proposal 1.67 15 Original NHK proposal, theatrical projection outside the U.S.
1.78 16 ATSC/SMPTE HDEP standard, optimized for shoot and protect 1.85 17 Theatrical projection in the U.S.
2.0 18 Most forms of VistaVision 2.2 20 Some widescreen movie formats 2.35 21 CinemaScope and similar movie formats 2.6 23 Cinerama 2.7 24 Dimension-150, Ultra-Panavision 2.77 25 Dynavision widescreen 3D film format 4.0 36 Polyvision
Industry:Entertainment
The nominal composite video signal level is 1 volt. At this level, a fully saturated image is transmitted and boosting the signal offers no advantage. Most video equipment is designed to output the same 1-volt level video signal. In cases where the signal level has been reduced, such as after a long cable run, an amplifier with video gain may be employed to restore the proper level.
Industry:Entertainment
