Definition
A device for directing a BEAM of RADIANT ENERGY successively over all points of a given region. In data processing a photo-electronic device for digital reproduction of pictures. The picture is scanned linewise and decomposed into a matrix-like raster of individual pixels. In contrast to vectorial DIGITIZERS, the information to coherent elements of the picture (lines, symbols) is lost by this rasterization process. To retrieve these elements the rasterized picture has to be vectorized by pattern recognition methods and manual post-processing.