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CHAPTER 4 Graphics
TABLE 4.21 Entries in a DeviceN color space attributes dictionary
KEY TYPE VALUE
Subtype name (Optional; PDF 1.6) A name specifying the preferred treatment for the color
space. Possible values are DeviceN and NChannel. Default value: DeviceN.
Colorants dictionary (Required if Subtype is NChannel and the color space includes spot colorants; other-
wise optional) A dictionary describing the individual colorants used in the
DeviceN color space. For each entry in this dictionary, the key is a colorant name
and the value is an array defining a Separation color space for that colorant (see
“Separation Color Spaces” on page 264). The key must match the colorant name
given in that color space.
This dictionary provides information about the individual colorants that may be
useful to some applications. In particular, the alternate color space and tint trans-
formation function of a Separation color space describe the appearance of that
colorant alone, whereas those of a DeviceN color space describe only the appear-
ance of its colorants in combination.
If Subtype is NChannel, this dictionary must have entries for all spot colorants in
this color space. This dictionary may also include additional colorants not used
by this color space.
Process dictionary (Required if Subtype is NChannel and the color space includes components of a pro-
cess color space, otherwise optional; PDF 1.6) A dictionary (see Table 4.22) that de-
scribes the process color space whose components are included in this color
space.
MixingHints dictionary (Optional; PDF 1.6) A dictionary (see Table 4.23) that specifies optional attributes
of the inks to be used in blending calculations when used as an alternative to the
tint transformation function.
A value of NChannel for the Subtype entry indicates that some of the other en-
tries in this dictionary are required rather than optional. The Colorants entry
specifies a colorants dictionary that contains entries for all the spot colorants in
the color space; they are defined using individual Separation color spaces. The
Process entry specifies a process dictionary (see Table 4.22) that identifies the pro-
cess color space that is used by this color space and the names of its components.
It must be present if Subtype is NChannel and the color space has process color
components. (An NChannel color space may contain components from at most
one process color space.)
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