Graphics Programs Reference
In-Depth Information
CHAPTER 7
Document Metadata and Navigation
In this chapter, we discuss four topics related not to the visual appearance of a PDF
document, but to the ancillary data which may also be included for interactive, onscreen
use of documents, and the metadata used to carry extra information with a document
for use by programs in a PDF workflow.
Destinations
Data structures defining a position within a file. They can be used to specify where
a
bookmark
or
hyperlink
points to. Bookmarks (properly called the
document out-
line
) are used as a table of contents for the document.
XML Metadata
A stream containing an XML file in a specified format, containing some of the same
metadata as the document information dictionary, together with additional fields.
File Attachments
Allow whole files to be encapsulated in a document, much like an email
attachment.
Annotations
Allow text and graphics to be applied on top of a PDF page, separate from the main
page content, for display by onscreen readers. One particular kind of annotation
is the
hyperlink
, which allows a user to click somewhere on a page and be redirected
to a destination elsewhere in the file.
Bookmarks and Destinations
A document's
bookmarks
(properly called the
document outline
) are a tree of entries
(typically titles of chapters, sections, paragraphs etc.) which can be clicked on in a PDF
viewer to move around the document. Each entry has some text and a
destination
de-
scribing where it links to.
