CHAPTER 10
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Document Interchange
TABLE 10.13 Additional dictionary entries for structure element access
KEY
TYPE
VALUE
StructParent
integer
integer
(Required for all objects that are structural content items; PDF 1.3)
The integer
key of this object’s entry in the structural parent tree.
(Required for all content streams containing marked-content sequences that are
structural content items; PDF 1.3)
The integer key of this object’s entry in the
structural parent tree.
Note:
At most one of these two entries may be present in a given object. An object
can be either a content item in its entirety or a container for marked-content
sequences that are content items, but not both.
StructParents
For a content item identified by an object reference, the parent structure element
can thus be found by using the value of the
StructParent
entry in the item’s object
dictionary as a retrieval key in the structural parent tree (found in the
ParentTree
entry of the structure tree root). The corresponding value retrieved from the
parent tree is a reference to the parent structure element (see Example 10.12).
Example 10.12
1 0 obj
<< /Type /StructElem
…
/K << /Type /OBJR
/Pg 2 0 R
/Obj 4 0 R
>>
>>
endobj
% Parent structure element
% Object reference
% Page containing form XObject
% Reference to form XObject
2 0 obj
% Page object
<< /Type /Page
/Resources << /XObject << /Fm4 4 0 R >>
% Resource dictionary
>>
% containing form XObject
/Contents 3 0 R
% Content stream
…
>>
endobj