Tutorials - Color Management for Photographers - page 320

Fig. 9-2-4 After choosing
the Assign Profile
command, click the Profile
radio button and try
picking different RGB
profiles.
on. Click the Profile radio button and select as many of the
color profiles you see in the list as you like. Try not only picking
Photoshop working spaces but also output spaces. A very
interesting result can be seen by picking e-sRGB ! See Fig. 9-2-4.
What you will notice is that the numbers in the info palette don't change
whatsoever but the color appearance does change. At first, this doesn't
make sense. We would think that R255/G130/B39 should always
produce the same preview since the numbers are fixed. However, this
illustrates a very critical concept that color numbers alone can't produce
the correct color appearance without first having a translator. The trans-
lator is, of course, an ICC profile. This profile takes the numbers and gives
them a meaning after which Photoshop has the information it needs to
produce the preview of this color.
Numbers alone can't show us what a color should look like. Although
it seems logical that a set of numbers is fixed (it is), ultimately what we
are doing is producing a color on-screen from nothing more than numeric
values of each pixel. Your images are no different from this one example
document we just produced, made up of thousands or millions of pixels
of different numbers. We see images but nonetheless, these images are
just huge lists of numeric values that our computers are able to repre-
sent as something that appears to us as a color photograph. Dismiss the
Assign Profile command by clicking the Cancel button. Close this doc-
ument and when asked to save, click Don't Save or just hold down the
D key.
Using a single document and changing its color space using the
Convert to Profile command, we can see how Photoshop will preserve
the color appearance of the image while changing the numeric value of
each pixel. Conversely, we will see how the same numbers in a docu-
ment can produce a different color appearance if the document's color
profile is changed using the Assign Profile command.
1. Open the Printer_Test_File.tif found on your CD.
2. If your Color Settings are such that you get an Embedded
Profile Mismatch , pick the radio button Use the embedded
profile (instead of the working space) to preserve the color
space of the document, thus allowing the document to open in