CHAPTER 4
212
Graphics
PARAMETER
TYPE
VALUE
soft mask
dictionary
or name
(PDF 1.4)
A
soft-mask dictionary
(see “Soft-Mask Dictionaries” on
used in the transparent imaging model (see “Source Shape and
or the name
None
if no such mask is specified. This parameter is
implicitly reset to its initial value at the beginning of execution of a
transparency group XObject (see Section 7.5.5, “Transparency
None
.
(PDF 1.4)
The constant shape or constant opacity value to be used
in the transparent imaging model (see “Source Shape and Opacity”
are two separate alpha constant parameters: one for stroking and
one for all other painting operations. This parameter is implicitly
reset to its initial value at the beginning of execution of a transpar-
ency group XObject (see Section 7.5.5, “Transparency Group
(PDF 1.4)
A flag specifying whether the current soft mask and al-
pha constant parameters are to be interpreted as shape values (
true
)
or opacity values (
false
). This flag also governs the interpretation of
the
SMask
entry, if any, in an image dictionary (see Section 4.8.4,
false
.
alpha constant
number
alpha source
boolean
TABLE 4.3 Device-dependent graphics state parameters
PARAMETER
TYPE
VALUE
overprint
boolean
(PDF 1.2)
A flag specifying (on output devices that support the
overprint control feature) whether painting in one set of colorants
should cause the corresponding areas of other colorants to be
erased (
false
) or left unchanged (
true
); see Section 4.5.6, “Overprint
one for stroking and one for all other painting operations. Initial
value:
false
.
(PDF 1.3)
A code specifying whether a color component value of 0
in a
DeviceCMYK
color space should erase that component (0) or
leave it unchanged (1) when overprinting (see Section 4.5.6, “Over-
overprint mode
number