CHAPTER 4
360
Graphics
KEY
TYPE
VALUE
OC
dictionary
(Optional; PDF 1.5)
An optional content group or optional content member-
ship dictionary (see Section 4.10, “Optional Content”) specifying the option-
al content properties for the form XObject. Before the form is processed, its
visibility is determined based on this entry. If it is determined to be invisible,
the entire form is skipped, as if there were no
Do
operator to invoke it.
(Required in PDF 1.0; optional otherwise)
The name by which this form
XObject is referenced in the
XObject
subdictionary of the current resource
dictionary (see Section 3.7.2, “Resource Dictionaries”).
Note:
This entry is obsolescent and its use is no longer recommended. (See
Name
name
on each side.
Example 4.31
6 0 obj
% Form XObject
<< /Type /XObject
/Subtype /Form
/FormType 1
/BBox [ 0 0 1000 1000 ]
/Matrix [ 1 0 0 1 0 0 ]
/Resources << /ProcSet [ /PDF ] >>
/Length 58
>>
stream
0 0 m
0 1000 l
1000 1000 l
1000 0 l
f
endstream
endobj
4.9.2 Group XObjects
A
group XObject (PDF 1.4)
is a special type of form XObject that can be used to
group graphical elements together as a unit for various purposes. It is distin-
guished by the presence of the optional
Group
entry in the form dictionary (see