CHAPTER 4
358
Graphics
TABLE 4.45 Additional entries specific to a type 1 form dictionary
KEY
TYPE
VALUE
Type
name
name
integer
(Optional)
The type of PDF object that this dictionary describes; if present,
must be
XObject
for a form XObject.
(Required)
The type of XObject that this dictionary describes; must be
Form
for a form XObject.
(Optional)
A code identifying the type of form XObject that this dictionary
describes. The only valid value defined at the time of publication is 1. Default
value: 1.
(Required)
An array of four numbers in the form coordinate system (see
above), giving the coordinates of the left, bottom, right, and top edges,
respectively, of the form XObject’s bounding box. These boundaries are used
to clip the form XObject and to determine its size for caching.
(Optional)
An array of six numbers specifying the
form matrix,
which maps
form space into user space (see Section 4.2.3, “Transformation Matrices”).
Default value: the identity matrix
[ 1 0 0 1 0 0 ]
.
(Optional but strongly recommended; PDF 1.2)
A dictionary specifying any
resources (such as fonts and images) required by the form XObject (see Sec-
In PDF 1.1 and earlier, all named resources used in the form XObject must be
included in the resource dictionary of each page object on which the form
XObject appears, regardless of whether they also appear in the resource dic-
tionary of the form XObject. It can be useful to specify these resources in the
form XObject’s resource dictionary as well, to determine which resources are
used inside the form XObject. If a resource is included in both dictionaries, it
should have the same name in both locations.
In PDF 1.2 and later versions, form XObjects can be independent of the
content streams in which they appear, and this is strongly recommended
although not required. In an independent form XObject, the resource dictio-
nary of the form XObject is required and contains all named resources used
by the form XObject. These resources are not promoted to the outer content
stream’s resource dictionary, although that stream’s resource dictionary refers
to the form XObject.
Subtype
FormType
BBox
rectangle
Matrix
array
Resources
dictionary