SECTION 4.5
287
Color Spaces
TABLE 4.24 Color operators
OPERANDS
OPERATOR
DESCRIPTION
name
CS
(PDF 1.1)
Set the current color space to use for stroking operations. The operand
name
must be a name object. If the color space is one that can be specified by a
name and no additional parameters (
DeviceGray
,
DeviceRGB
,
DeviceCMYK
, and
certain cases of
Pattern
), the name may be specified directly. Otherwise, it must
be a name defined in the
ColorSpace
subdictionary of the current resource dic-
tionary (see Section 3.7.2, “Resource Dictionaries”); the associated value is an
array describing the color space (see Section 4.5.2, “Color Space Families”).
Note:
The names
DeviceGray
,
DeviceRGB
,
DeviceCMYK
, and
Pattern
always iden-
tify the corresponding color spaces directly; they never refer to resources in the
ColorSpace
subdictionary.
The
CS
operator also sets the current stroking color to its initial value, which de-
pends on the color space:
•
In a
DeviceGray
,
DeviceRGB
,
CalGray
, or
CalRGB
color space, the initial color
has all components equal to 0.0.
•
In a
DeviceCMYK
color space, the initial color is
[ 0.0 0.0 0.0 1.0 ]
.
•
In a
Lab
or
ICCBased
color space, the initial color has all components equal to
0.0 unless that falls outside the intervals specified by the space’s
Range
entry,
in which case the nearest valid value is substituted.
•
In an
Indexed
color space, the initial color value is 0.
•
In a
Separation
or
DeviceN
color space, the initial tint value is 1.0 for all colo-
rants.
•
In a
Pattern
color space, the initial color is a pattern object that causes nothing
to be painted.
name
c
1
…
c
n
cs
SC
(PDF 1.1)
Same as
CS
but used for nonstroking operations.
(PDF 1.1)
Set the color to use for stroking operations in a device, CIE-based
(other than
ICCBased
), or
Indexed
color space. The number of operands re-
quired and their interpretation depends on the current stroking color space:
•
For
DeviceGray
,
CalGray
, and
Indexed
color spaces, one operand is required
(n
=
1).
•
For
DeviceRGB
,
CalRGB
, and
Lab
color spaces, three operands are required
(n
=
3).
•
For
DeviceCMYK
, four operands are required (n
=
4).