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SECTION 4.3 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-
tion 6.2.3, “Conversion from DeviceRGB to DeviceCMYK”). Initial
value: installation-dependent.
undercolor removal function or name (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,
“Conversion from DeviceRGB to DeviceCMYK”). Initial value: in-
stallation-dependent.
transfer function, (PDF 1.2) A function that adjusts device gray or color component
array, or name levels to compensate for nonlinear response in a particular output
device (see Section 6.3, “Transfer Functions”). Initial value:
installation-dependent.
halftone dictionary, (PDF 1.2) A halftone screen for gray and color rendering, specified
stream, or name as a halftone dictionary or stream (see Section 6.4, “Halftones”).
Initial value: installation-dependent.
flatness number 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.
smoothness number (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-
ance”). The value of this parameter gives the maximum error
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.
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.
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