Do You Need Color Management - Adobe PHOTOSHOP 6.0 Manual

CHAPTER 4
122
Producing Consistent Color (Photoshop)
created to the color space in which the same color
will be output, and makes the necessary adjust-
ments to represent the color as consistently as
possible among different devices.
Note: Don't confuse color management with color
adjustment or color correction. A CMS won't correct
an image that was saved with tonal or color balance
problems. It provides an environment where you can
evaluate images reliably in the context of your final
output.
Photoshop follows a color management workflow
based on conventions developed by the Interna-
tional Color Consortium (ICC). The following
elements and concepts are integral to such a color-
managed workflow.
Color management engine
have developed various ways to manage color.
To provide you with a choice, a color management
system lets you choose a color management engine
that represents the approach you want to use.
Sometimes called the color management module
(CMM), the color management engine is the part
of the CMS that does the work of reading and
translating colors between different color spaces.
Color numbers
has a set of color numbers that describe the pixel's
location in a particular color mode—for example,
red, green, and blue values for the RGB mode.
However, the actual appearance of the pixel may
vary when output or displayed on different
devices, because each device has a particular way
of translating the raw numbers into visual color.
(See "Why colors sometimes don't match" on
Different companies
Each pixel in an image document
page 121.) When you apply color and tonal
adjustments or convert a document to a different
color space, you are changing the document's
color numbers.
An ICC workflow uses color profiles
Color profiles
to determine how color numbers in a document
translate to actual color appearances. A profile
systematically describes how color numbers map
to a particular color space, usually that of a device
such as a scanner, printer, or monitor. By associ-
ating, or tagging, a document with a color profile,
you provide a definition of actual color appear-
ances in the document; changing the associated
profile changes the color appearances. (For infor-
mation on displaying the current profile name in
the status bar, see "Displaying file and image infor-
mation" on page 78.) Documents without
associated profiles are known as untagged and
contain only raw color numbers. When working
with untagged documents, Photoshop uses the
current working space profile to display and edit
colors. (See "About working spaces" on page 125.)

Do you need color management?

Use the following guidelines to determine whether
or not you need to use color management:
You might not need color management if your
•
production process is tightly controlled for one
medium only, for example, if you're using a closed
system where all devices are calibrated to the same
specifications. You or your prepress service
provider may prefer to tailor CMYK images and
specify color values for a known, specific set of
printing conditions.