User`s manual

Chapter 1 - Introduction
2
FastRIP 10.0 User’s Manual
PostScript and Raster Images
e term “raster display” originates from the method by which television images are created in
a series of horizontal scan lines. Sixty times a second (60 Hz), these scan lines are rendered from
top to bottom on a cathode-ray tube (CRT). is frequency is faster than the brain can process
the information, thus allowing a sequence of still pictures to create the illusion of movement.
Televisions and computer monitors are referred to as raster displays and the rectangular pattern
of horizontal lines refers to a raster.
A printer is also considered a raster display, since printing requires text and graphics to be trans-
lated into a rectangular pattern of horizontal lines. e printer will then lay ink upon the media
for each raster line, rendering the final image. e process of creating a Raster from text and
graphic elements is known as “rasterization.”
PR I n t e R s - Po s t sc R I P t v e R s u s no n -Po s t sc R I P t
A PostScript file is a computer file that contains page layout descriptions for a print job. e
term “PostScript Printer” originated in the late 1980’s to describe printers designed to receive
PostScript files from networked computer terminals. When computers were not nearly as power-
ful as today’s machines, a central printer would be customized with expensive memory and an
upgraded microprocessor. is printer could then combine a PostScript file with printer-resident
fonts, as well as any graphics or additional fonts that were transmitted with the PostScript file.
is printer would then perform the raster image processing (RIP) task and output the results.
Using a PostScript printer was considered efficient because it did not require each of the net-
worked computers to handle the complicated rasterization process. Each computer was only
required to transmit a relatively small PostScript file, which placed very little demand upon the
network.
e term “Non-PostScript Printer” originated in the early 1990’s. As PC’s became faster and larg-
er amounts of internal RAM became standard, printers no longer had to act as image processors.
With less on-board memory and fewer tasks to process, these “dumb” printers were significantly
less expensive and they could print much faster. e task of rasterizing the PostScript data was
now the responsibility of each desktop or laptop within the network. e printer would merely
receive the raster data and produce an output, making no modifications.