Image Processing Reference
In-Depth Information
1
An Overview of Digital
Printing Systems
1.1 INTRODUCTION
The printing industry includes a number of segments [1] including commercial
printing and publishing. The integration of computing, imaging, and controls tech-
nology has enabled advanced digital color printing and publishing systems for the
of
ce and production.
In this chapter, we describe some of the key elements of an end-to-end digital
printing and publishing system used for the production of high print volumes and the
management of complex print jobs. This overview will help the reader to better
understand the functional and processing system-level components involved when
designing optimal printing systems.
1.2 PRINTING AND PUBLISHING SYSTEM
Printing and publishing is a large industry composed of many shops, that vary in
size. These shops use equipments based on a variety of printing methods. Litho-
graphy, letterpress,
flexography, gravure, and screen-printing use plates or some
other form of image carrier, and digital or electronic printing such as electrostatic or
ink-jet is plateless. Lithography, often called
is the dominant
printing process in the industry. Flexography produces vibrant colors with little
rub-off qualities, valued for newspapers, directories, and books. Gravure
offset printing,
''
''
s high-
'
quality reproduction,
flexible pagination and formats, and consistent print quality are
used in packaging and printing of periodicals.
In offset printing presses, the press control system controls and monitors the ink,
water, and print registration systems, and often robots are used to move parts in and
out of the presses in print shops [2]. Unlike digital printers, the traditional offset
press does not allow the changing of pixels on page boundaries while printing. This
limitation brings new challenges and opportunities to the digital printing and pub-
lishing value chain.
Some publishing processes became digital for several reasons: (1) variable
information electronic documents containing fragments of text, graphics, and images
from either the electronic or the scanned input stream can be merged, edited, and
assembled into laid-out pages forming a complete job; (2) the printing technology
can handle digital stream of data; and (3) the bene
ts of digital data brought
additional value, for example,
. This led to variable data printing
with a lower cost short run, personalization, and versioning, that is dif
'
print-on-demand
'
cult to create
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