scanner

In computer graphics, a device that sequentially samples and records digitally the color and intensity of successive elements of an object or image (e.g., a flat, paper object such as a photograph or drawing), for digital storage, transmission, or processing. Note: The collected data are usually stored in one of several computer graphics formats. 2. In television technology, a device that (a) scans successive frames (images) on motion-picture film, and (b) transcodes the digital data so obtained into an electronic signal (e.g., analog NTSC signal, or other signal, including a digital signal) that conforms to any standard or accepted video format. Note: Scanners may also scan video images in non-real-time transcoding. The scanner may provide input to a recorder, to a signal processor, to a transmission channel, or to any other desired peripheral system. 3. In computer (specifically, word-processing) technology, a device that examines text, e.g., on a printed page, and applies certain character-recognition algorithms or principles to determine the text elements (letters, numerals, and other characters) in sequence and convert them into standard (e.g., ASCII) digital code for storage or further processing. Note: This special application of character-recognition technology eliminates laborious manual transcription of text, by keyboard entry, into digital files. 4. A device that examines a spatial pattern, one part after another, and generates analog or digital signals corresponding to the pattern. Note: Scanners are often used in mark sensing, pattern recognition, and character recognition. 5. A radio receiver that is automatically and rapidly tuned (i.e., sweeps) across a predetermined range of frequencies (band), locking onto any frequency at which a signal is detected. Note: A scanner provides a means of monitoring a range of frequencies, and any traffic that may be present, but will usually not permit the simultaneous monitoring of more than one frequency.