CMS Utilities - Color Management for Photographers - page 281

information about the internal structure of the profile. Items listed are
the tables that make up the profile as well as items known as private tags,
copyright notice, and so forth.
The top entry, Description , provides basic information about the profile
such as the size, preferred CMM specified when the profile was built, the
color model, date of creation, and preferred rendering intent. The second
entry ( cprt ) shows copyright information, which usually is created by the
product that built the profile. I will often look at this tag when someone
sends me a profile and I wish to see what software generated the profile.
Depending on the profile structure, there may be a number of additional
tags you can click to see additional information. For example, the profile
seen in Fig. 8-4 is built from ProfileMaker Pro, which produces three
ASCII text strings that provide additional data such as the spectral mea-
surements of the target used to build the profile.
This information can change a great deal depending on the profile and
how it was built. These tags are known as Private Tags since they are open
for profile manufacturers to use as they wish. This kind of information
can be used by the application that created the profile for certain unique
features. For example, the private tag that contains the measured data
allows ProfileMaker Pro to import a profile should the user wish to build
a new profile but may not have the original measurement data.
A private tag may contain specific information about the options used
to build that profile. In virtually all cases, private tags contain data that
often is useful and available only to the product that originally built that
profile. Double-click the profile in the list while holding down the Option
key, or click a tag in the list in the Profile Document window while
holding down the Option key. This brings up a text view that shows the
Fig. 8-4 Three different tags are viewed here in the ColorSync utility from a ProfileMaker Pro output profile. I've grayed out the other tags
so it is easier to see which are being selected with the tag information displayed below the list of tags. Seen here are LAB, Spectral data,
and specifics as to how the profile was built, and data available in tag 3-5.