APPENDIX F
1022
Linearized PDF
longer linearized and subsequently is treated as ordinary PDF. Linearizing it
again may require reprocessing the entire file; see Section F.4.6, “Accessing an Up-
Linearized PDF requires two additions to the PDF specification:
•
Rules for the ordering of objects in the PDF file
•
Additional data structures, called
hint tables,
that enable efficient navigation
within the document
Both of these additions are relatively simple to describe; however, using them
effectively requires a deeper understanding of their purpose. Consequently, this
appendix goes considerably beyond a simple specification of these PDF exten-
sions to include background, motivation, and strategies.
•
about the properties of the Web that are relevant to the design of Linearized
PDF.
•
object-ordering requirements of Linearized PDF.
•
tables.
•
over a network, which in turn determine the optimal way to organize the PDF
file.
The reader is assumed to be familiar with the basic architecture of the Web, in-
cluding terms such as URL, HTTP, and MIME.
F.1 Background and Assumptions
The principal problem addressed by the Linearized PDF design is the access of
PDF documents through the Web. This environment has the following important
properties:
•
The access protocol (HTTP) is a transaction consisting of a request and a re-
sponse. The client presents a request in the form of a URL, and the server sends
a response consisting of one or more MIME-tagged data blocks.