CHAPTER 10
970
Document Interchange
KEY
TYPE
VALUE
ColorSpace
array
(Optional)
An array defining a
Separation
or
DeviceN
color space (see “Separa-
provides additional information about the color specified by
DeviceColorant
—in
particular, the alternate color space and tint transformation function that would
be used to represent the colorant as a process color. This information enables a
viewer application to preview the separation in a color that approximates the de-
vice colorant.
The value of
DeviceColorant
must match the space’s colorant name (if it is a
Separation
space) or be one of the space’s colorant names (if it is a
DeviceN
space).
10.10.4 Output Intents
Output intents (PDF 1.4)
provide a means for matching the color characteristics
of a PDF document with those of a target output device or production environ-
ment in which the document will be printed. The optional
OutputIntents
entry in
the document catalog (see Section 3.6.1, “Document Catalog”) holds an array of
output intent dictionaries,
each describing the color reproduction characteristics
of a possible output device or production condition. The contents of these dictio-
naries can vary for different devices and conditions. The dictionary’s
S
entry
specifies an
output intent subtype
that determines the format and meaning of the
remaining entries.
This use of multiple output intents allows the production process to be custom-
ized to the expected workflow and the specific tools available. For example, one
production facility might process files conforming to a recognized format stan-
dard such as PDF/X-1, while another uses custom Acrobat plug-in extensions to
produce
RGB
output for document distribution on the Web. Each of these work-
flows would require different sets of output intent information. Multiple output
intents also allow the same PDF file to be distributed unmodified to multiple pro-
duction facilities. The choice of which output intent to use in a given production
environment is a matter for agreement between the purchaser and provider of
production services. PDF intentionally does not include a selector for choosing a
particular output intent from within the PDF file.
At the time of publication, only one output intent subtype,
GTS_PDFX
, has been
defined, corresponding to the PDF/X format standard specified in ISO 15930-
1:2001 (
see the Bibliography
). Table 10.51 shows the contents of this type of output