SECTION 4.3
213
Graphics State
PARAMETER
TYPE
VALUE
black generation
function or name
(PDF 1.2)
A function that calculates the level of the black color
component to use when converting
RGB
colors to
CMYK
(see Sec-
value: installation-dependent.
(PDF 1.2)
A function that calculates the reduction in the levels of
the cyan, magenta, and yellow color components to compensate for
the amount of black added by black generation (see Section 6.2.3,
stallation-dependent.
(PDF 1.2)
A function that adjusts device gray or color component
levels to compensate for nonlinear response in a particular output
device (see Section 6.3, “Transfer Functions”). Initial value:
installation-dependent.
(PDF 1.2)
A halftone screen for gray and color rendering, specified
as a halftone dictionary or stream (see Section 6.4, “Halftones”).
Initial value: installation-dependent.
The precision with which curves are to be rendered on the output
device (see Section 6.5.1, “Flatness Tolerance”). The value of this
parameter gives the maximum error tolerance, measured in output
device pixels; smaller numbers give smoother curves at the expense
of more computation and memory use. Initial value: 1.0.
(PDF 1.3)
The precision with which color gradients are to be ren-
dered on the output device (see Section 6.5.2, “Smoothness Toler-
tolerance, expressed as a fraction of the range of each color compo-
nent; smaller numbers give smoother color transitions at the
expense of more computation and memory use. Initial value:
installation-dependent.
undercolor removal
function or name
transfer
function,
array, or name
halftone
dictionary,
stream, or name
number
flatness
smoothness
number
Some graphics state parameters are set with specific PDF operators, some are set
by including a particular entry in a
graphics state parameter dictionary,
and some
can be specified either way. The current line width, for example, can be set either
with the
w
operator or (in PDF 1.3) with the
LW
entry in a graphics state parame-
ter dictionary, whereas the current color is set only with specific operators, and
the current halftone is set only with a graphics state parameter dictionary. It is
expected that all future graphics state parameters will be specified with new
entries in the graphics state parameter dictionary rather than with new operators.