To prepare data for display or printing. All data delivered to a screen or printer must be in the form of a matrix of pixels or dots (a bitmap), which is rendered one line at a time. The only exception is a vector plotter, which accepts vector images and literally draws with pens (see vector graphics
). The bitmaps are created by rasterizing software in the computer or a raster image processor (RIP) chip in the graphics card or printer.
There are generic rasterizing routines as well as routines for specific formats such as PostScript, PDF, vector fonts and vector drawings. Images natively in bitmap formats also have to be scaled into screen and printer bitmaps. See RIP
, raster scan
, font scaler
and host-based printer