Definitions for "Drum scanner"
A high quality, high priced device which uses photomultiplier tubes to translate an image from analog to digital. Drum scanners are much larger than desktop scanners and give the operator much more control over image manipulation while scanning. Images are mounted on a round cylinder, or drum, for scanning. A scanner passes a moving beam of light over an image and receives data about the color or value of each spot in the image. These spots are assigned values from 0-256 so that computers can display them.
A type of scanner in which a map, diagram or photograph is placed on a cylinder which rotates slowly while a scanning beam quickly moves back and forth parallel to the revolving image. At the same time, the "x,y" coordinates and spectral signature of each element of the image are recorded. (See Scanner).
A type of SCANNER in which the original to be scanned is wrapped around a glass cylinder and spun at high speed, while a light-sensing device called a PHOTOMULTIPLIER TUBE scans across the cylinder. Drum scanners offer much higher resolution, greater tonal reproduction, higher DYNAMIC RANGE, and greater control over the scanned image than FLATBED SCANNERS do, and allow the image to be COLOR CORRECTED as the scan is being made. Most drum scanners also allow scanning of very large originals. However, drum scanners are very expensive (ranging in price from tens of thousands of dollars to a quarter-million dollars or more) and require a high degree of technical expertise to operate.