DLI Implementation and Reference Guide - Datalogics

Color and its Use 12.7
Basic Color Spaces
The Device color spaces below presume to render color as an absolute value. These
are the basic color spaces, and are fully supported throughout PDF and PostScript.
CIE Calibrated Color Spaces
Calibrated color spaces are colors with perception qualifiers. These are defined by CIE
and are intended to permit a more faithful rendition of color, given a knowledge of the
display device characteristics.
A full discussion of the CIE models is beyond the scope of this document, but you can
find a great deal of information on them in the Adobe PDF Specifications document
or the PostScript Language Reference.
Device Gray
This space allows you to use black and white or levels of gray. It has a single channel
of color data, which is viewed by the imaging engine as a value between 1 (White) and
zero (Black).
Since the value is specified to the system as an ASFixed value, 16 bits of precision are
possible. Generally, this will be rounded down to 4 decimal positions of precision
when written to the PDF file.
The atom used to create this color model is DeviceGray. It is assumed to be present
in all levels of PDF, and does not need to be added to the resource directory as a color
space name.