olemus
Wiktionary:
1. (electronics) a scanning pattern of parallel lines that form the display of an image projected on a cathode-ray tube of a television set or display screen
2. (computer graphics) a bitmap image, consisting of a grid of pixels, stored as a sequence of lines

raster display -- rasterkuva
raster graphics -- rastergraafika
raster image -- rasterpilt
rasterization -- rsterdus
raster scan -- rasterskaneerimine
raster unit -- rastri samm

ülevaateid
https://en.wikipedia.org/wiki/Raster