SECTION F.2
1035
Linearized PDF Document Structure
Resources
and
MediaBox
; the attributes cannot be inherited from ancestor page
tree nodes.
•
The entire outline hierarchy, if the value of the
PageMode
entry in the catalog
is
UseOutlines
. (If the
PageMode
entry is omitted or has some other value and
the document has an outline hierarchy, the outline hierarchy appears in part 9;
see Section F.2.9, “Other Objects (Part 9)” for details.)
•
All objects that the page object refers to, to an arbitrary depth, except page tree
nodes or other page objects. This includes objects referred to by its
Contents
,
Resources
,
Annots
, and
B
entries, but not the
Thumb
entry.
The order of objects referenced from the page object should facilitate early user
interaction and incremental display of the page data as it arrives. The following
order is recommended:
1. The
Annots
array and all annotation dictionaries, to a depth sufficient for
those annotations to be activated. Information required to draw the annota-
tion can be deferred until later since annotations are always drawn on top of
(hence after) the contents.
2. The
B
(beads) array and all bead dictionaries, if any, for this page. If any beads
exist for this page, the
B
array is required to be present in the page dictionary.
Additionally, each bead in the thread (not just the first bead) must contain a
T
entry referring to the associated thread dictionary.
3. The resource dictionary, but not the resource objects contained in the dic-
tionary.
4. Resource objects, other than the types listed below, in the order that they are
first referenced (directly or indirectly) from the content stream. If the contents
are represented as an array of streams, each resource object should precede the
stream in which it is first referenced. Note that
Font
,
FontDescriptor
, and
Encoding
resources should be included here, but not substitutable font files
referenced from font descriptors (see item 7 below).
5. The page contents (
Contents
). If large, this should be represented as an array
of indirect references to content streams, which in turn are interleaved with
the resources they require. If small, the entire contents should be a single con-
tent stream preceding the resources.
6. Image XObjects, in the order that they are first referenced. Images are assumed
to be large and slow to transfer; therefore, the viewer application defers ren-
dering images until all the other contents have been displayed.