Labels:text | black and white | font | document | screenshot OCR: Note: terms follo wed by an asterisk (*) have individual articles. analog - Information that is reproduced using a continuously varying electronic signal. In video terms, its opposite is digital. aspect ratio - The proportions of a TV or film picture, generally given as the ratio of width to height. The standard TV picture has an aspect ratio of 4 X 3, or 4:3. High-definition video systems may have aspect ratios of 5 X 3 or greater. bandwidth - The range of frequencies required for transmitting different types of electronic signals. Color TV needs a broad band-about 4.6 MHz; the telephone requi res only a narrow band, less than 4 kHz. Beta - The first successful home videocassette system, using 1/2-inch (1.27-cm) tape. C-band - The portion of the microwave spectrum (4,000-8,000 MHz) used most widely for distribution of video programs by satellite to cable systems. cable TV* - Method of nonbroadcast distribution of video programs directly to homes, generally employing coaxial or fiber-optic cable. camcorder - One-piece combination video camera and recorder. carrier wave - An electronic signal that is capable of carrying information when the signal is modulated. CATV - Community antenna television; the predecessor of cable TV. The initials now often refer to cable TV. CCD (charge-coupled device*) - A semiconductor chip used as a highly efficient ight sensor in video cameras COR - Intemational Radio Consultative Committee; a United Nations technical body that coordinates world broadcasting. The initials also refer to the 625-line, 50-frame TV system used in most European countries. CCTV - dosed-circuit television. CD-I - Compact Disc-Interactive; a multimedia, video-displayable CD, accessible through a CD-I player, with a handset allowing viewer interaction. CD-ROM - Compact Disc-Read Only Memory; a laser-read, computer-accessible disc that stores massive quantities of digiti zed data. COMSAT - Communication Satellite Corporation; providing satellite communication services and chartered by the federal govemment. CRT (cathode ray tube*) - The screen usually used on a TV set or on a computer terminal database* - Computerized store of information that can be reached only via a computer. DBS - Direct Broadcast Satellite; a system that sends TV broadcasts directly from a communications satellite to home antennas, or dishes. digital television - TV transmission in the form of binary data making possible more precise processing of the picture. Digital signal processing (DSP) - Describes various digital processes to enhance analog transmission. dish - The parabolic antenna used for transmitting and receiving signals from communication satellites. DOMSAT - Domestic communication satellite (as opposed to one confined to Earth station - The ground station that receives (downlink) and sends (uplink) signals military uses). to and from communication satellites. edit, electronic edit - The removal, or the joining together, of sections of film or videotape material. In film editing, the material is actually cut out, or pasted together mechanically. In electronic editing of videotapes, videotape recorders make the requi red changes electronically. electronic image stabilizer (EIS) - A digital feature in some camcorders that compensates for unintended camera movement. ENG - Bectronic newsgathering; the use of video cameras and tape recorders in place of film systems for news coverage by TV stations. ETV - Educational television. FAX (facsimile* transmission) - A system that transmits pictures or print electronically. field - A set of scanning lines that, when interlaced with another set, makes up the "frame," or complete TV picture. footprint - The particular patch of the Earth's surface reached by the signal from a communications satellite. frame - A complete TV picture, comprising two fields. The U.S. transmission standard calls for 30 frames transmitted per second. frequency* - The number of cydes per second of an electromagnetic transmission. 1 hertz (Hz) = 1 cyde per second; 1 kilohertz (kHz) = 1,000; 1 megahertz (MHz) = 1,000,000; 1 gigahertz (GHz) = 1 billion. front projection - A type of projection TV system in which the picture is projected onto a reflective screen, which is viewed from the same side as the source of the projected picture. fuzzy logic - A form of artificial intelligence, stored on a computer chip, that enables a camcorder or television to make complex adjustments in focus or picture quality based on ideal models. geostationary orbit - The orbit of a communications satellite that allows it to move at the precise speed at which the Earth is rotating, thus remaining at the same spot in the sky relative to the Earth. The orbit is 35,900 km (22,300 mi) above the Earth and directly over the equator. HDTV- High-definition TV *; a technology aimed at producing a video picture containing as much detail as a 35-mm motion picture, with wide-screen aspect ratio and stereophonic sound. head - In video and audio, and electromagnetic device that both lays down the magnetic track on recording tape and reads an existing track. helical scan - The basis for most modem videotape reco iding, in which the signal is recorded as a diagonal track by recording heads on a rapidly revolving drum. The same heads, revolving at the same speed, are used for playback. IN TEL SAT* - International Telecommunications Satellite Organization; 112-member consortium of countries fo med (1964) to launch and operate communications satellites. kinescope - A TV picture tube. Also, a photographic film made from a TV transmission as it appears on the tube. Once used for recording TV programs, it has been replaced by videotape recording. Ku-band - The portion of the microwave spectrum (12,000-18,000 MHz) used in many newer video satellite transmissions, particularly in Direct Broadcast Satellite (DBS) systems designed for home reception. LaserVision, Laser Disc - Trade names for the optical videodisc* system in which picture and sound are recorded, and read out by laser. LCD (liquid crystal* display) - A thin, flat glass "sandwich" enclosing a layer of voltage-sensitive liquid. Widely used for calculator and watch displays and, more recently, for portable computer readouts and "pocket television" screens. LPTV - Low-power TV; TV station with limited broadcasting range, often built in rural areas in order to pick up and amplify distant signals. Also used for broadcast programming to specific audiences lux - Unit of light illuminance. Used as a measure of lowlight recording capacity in video cameras. MATV - Master antenna television; a distribution system in which a single antenna is used to feed broadcast TV signals to the occupants of a building or development. SMATV provides the same service but uses a dish antenna to pick up satellite transmissions . MDS - Multipoint distribution service; a method of distributing video programs from a central high point (usually a tall building) by microwave to subscribers equipped with special antennas. Sometimes called "wireless cable." modem* - A device used for accessing computer data over telephone lines. monitor - A video display used in TV studios and designed to receive direct input of video signals from studio cameras, videotapes, and other signal-producing equipment. monitor-receiver - A television receiver that has video inputs enabling it also to serve as a monitor. MTS - Multichannel TV sound; provides additional sound channels along with a single picture on a TV channel. The U.S. transmission system can include stereophonic sound as well as additional sound channels. narrowcasting - Transmission to a specific, small audience (such as Japanese-speaking people, for example), often via lowpower, UHF stations. NTSC- National Television System Committee; a U.S. industry body that developed the black-and-white and color transmission standards used in most Westem Hemisphere countries, in Japan, and in some other East Asian countries. The NTSC system uses a picture composed of 525 horizontal lines with 30 frames (complete pictures) transmitted per second. PAL - Phase Altemation Line color system; the color TV broadcast standard used in most of Westem Europe and, in modified form, in China and Brazil. pay cable - Scrambled TV pictures of premium programs, transmitted by cable, designed for viewing only by those paying a monthly fee for home decoders. pay-per-view, PPV - A form of pay TV where a specified fee is paid for watching each program selected. perceptual coding - A technique of data compression in which the video and audio signals that will not register on the eye or ear are filtered out so that fewer bits are needed for accurate reproduction. picture in picture, PIP - A television feature in which a small screen can be displayed within the large screen, allowing the viewer to watch (though not hear) two channels simultaneously. The second picture must usually be sourced through a VCR, although there are televisions with two tuners. pixel - Picture element; the smallest area of a video picture capable of being delineated by an electrical signal. The number of pixels in a complete picture determines the amount of detail or resolution in the picture. In the United States the TV picture generally holds a maximum of 150,000 pixels. projection television - A television or video display system in which the picture is projected onto a screen, generally from three separate cathode ray tubes, one for each primary color. pulse-code modulation - One method of digitalizing an analog signal. rear projection - A projection TV system wherein the picture is projected onto a translucent screen, which is viewed from the opposite side. resolution - Standard measurement of the amount of detail that can be seen in a TV-screen image, expressed in the number of horizontal lines on a test pattem. RF - Radio frequency; the electromagnetic wave "camier" that conveys the modulated video signal from a TV station to a home receiver. SATCOM - RCA's communication satellites. scrambling - A method of a tering a cable or satellite transmission signal so that it can be seen only by those who own special decoders. SECAM - Sequentiel Couleur avec Memoire (sequential color with memory); the color TV broadcast standard used in France and its former possessions and, in modified form , in the USSR and some Eastem European countries. SMATV - See MATV STV - Subscription TV; broadcast TV, transmitted in scrambled form, for which a decoder is needed. teletext* - System of transmission of alphanumeric and other graphic information by TV stations along with their standard programs, for reception only by specially equipped TV receivers. transponder - Device on a communications satellite that receives electromagnetic signals and transmits them back to Earth. TVRO - TV receive-only Earth station; such as a home dish antenna. UHF - Ultra high frequencies; used by TV channels 14 to 82. VCR - Videocassette recorder; in which the tape is enclosed in a cassette and the loading within the machine is automatic. VDT - Video display terminal *; generally used with a computer. vertical blanking interval (VBD) - The 21 lines between TV frames, transmitted, like the frames, at a rate of 30 times per second. These lines are used for auxiliary information, including teletext, dosed captions, and test signals. VHD - Video High Density (or Video Home Disc); agrooveless record whose video signals are read by a floating stylus. VHF - Very high frequencies; used by TV channels 2 to 13. VHS - A videocassette format, using 1/2-inch (1.27-cm) tape. VHS-Cis a smaller VHS cassette. Super-VHS (S-VHS) incorporates advanced digital circuitry. videodisc* - A disc resembling a phonograph record that stores both picture and sound for playback. videotex* - Interactive (two-way) system for accessing written and graphic information on video screens and computer display terminals, which are linked to central computers via telephone lines. VTR - Videotape recorder, using either cassettes or open reels.
