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Research and Realization about Conversion
Algorithm of PDF Format into PS Format
Xingfu Wang, Lei Qian, Fuyou Mao, and Zhaosheng Zhu
School of Computer Science & Technology in the University of Science and Technology of China,
USTC,Hefei, Anhui, P.R.China postalcode: 230027
wangxfu@ustc.edu.cn, mfy@ustc.edu.cn
Abstract—This paper firstly introduces the characteristics of
PostScript document and PDF document as the basis, and
proposes the necessity and the feasibility of the conversion
from the PDF document format to the PostScript language
program. Secondly, it studies the main algorithm and
technology of the conversion process and realizes the
information extraction for PDF document lastly, with
achieving the software algorithm for the conversion from
PDF document format into PS format on the basis of the
text.
Index Terms—PDF PS(PostScript), Format conversion,
Object-oriented, Interpreter
I. INTRODUCTION
PDF (Portable Document Format), developed by
Adobe, is a open electronic file format which is suitable
for transmitting and sharing the file between the different
computer system, with the advantages like cross-platform,
high-compression, being suitable for screen viewing and
network transmission, the protection of documents, e-
reviewed, Print output of higher quality. PS language
(PostScript description language, namely PDL), is also a
matter of fact in the printing industry standard owned by
Adobe, which may describe the exquisite layout and
occupy the dominant position in the area of printing
presently. Though PDF develops on the basis of
PostScript, it is not a programming language, hence it
must be converted to PostScript date flow when the
output is on the common PostScript printer, or the PDF
document must be converted to PS document before the
output.
II.
CHARACTERISTICS AND STRUCTURES OF PS
LANGUAGE
PostScript language as a common page description
language in the modern printing technology is one kind
of Interpretative programming languages, with strong
graphics function. PostScript language takes Adobe's
imaging model theory as the basis for the description of
pages, and its main application is printing pages or
describing text, graphics, shape and sampling images on
the display pages. The procedures, wrote by using
PostScript language, might describe the correspondence
from Organizing layout system to printing system by
documents, or control displayed result of objects on the
display. The description produced by PostScript language
This work is supported by National Natural Science Foundation of
China (NO.60773037&60970128), by Teaching Research Project of
Anhui Province (2007)
© 2010 ACADEMY PUBLISHER
AP-PROC-CS-10CN006
ISBN 978-952-5726-09-1 (Print)
Proceedings of the Second International Symposium on Networking and Network Security (ISNNS ’10)
Jinggangshan, P. R. China, 2-4, April. 2010, pp. 031-034
31
is a high-grade description, and it is noting with the
equipment, thus it has become an important and
indispensable component of the high-quality printing and
output. At present, many printers, film Phototypesetters,
printing Phototypesetters, digital printers and other
equipments have all been installed the PostScript
interpreter; many RIP processing software also take
PostScript interpreter as its core technology, and many
image-processing software, graphics and design software
and typesetting software support PostScript as also, in
which the most famous typical software are Photoshop,
CorelDraw, Illustrator, Freehand, QuarkXPress,
PageMaker, and so on.
A. The basic characteristics of PostScript language
Compares with other file formats, PostScript language
has the capacity of page description and interactive
handling ability between text and images. In addition,
PostScript document has many advantages. For example,
one of the advantages is that PostScript document is
independent of the equipment and independent of the
operating system platform. Graphical environment of
UNIX itself takes the support of PostScript as its core
part, so no matter using Windows operating system or
using UNIX operating system, PostScript document can
be read and print well, hence it is convenient to exchange.
Moreover, although the PostScript documents also use
the binary encoding to save, it generally expresses and
stores information by the text mode of ASCII code, by
which it can be easier to read and edit.
B. The composition of PS document and the
characteristics of procedures
PostScript language is a high-level interpretative
language, which has a wealth of data types and the
control statement. Besides, it proposes the concept of the
process and, like other programming languages (such as
the C language), adopts the structured programming
method of the top-down and stepwise refinement. A
PostScript file with a good structure is usually composed
of two parts: preface part and description part.
Syntax, data types and implementation of semantics is
the three basic parts of any a PostScript procedure.
Coupled with its outstanding capacity of the graphics,
images and text, the PostScript language can be
competent to control and print the task of dealing with
pages. The grammar of PostScript language is quite
simple, but its function is very powerful, which comes
from it can without any restrictions to combine its each
characteristic in any way. Using these functions of PS