Graphics Programs Reference
In-Depth Information
complain that documents in Photoshop don't match the color appearance
in other applications. The other applications are not showing the
numbers correctly. Photoshop, when set up correctly, does. This is
demonstrated in the tutorial, “Color Documents and Color Appearance”
mentioned in Chapter 1.
Working (Editing) Spaces also Divorce Editing from
the Monitor
The next area the Adobe team addressed was a way to work with docu-
ments in specific editing spaces, which they called
working spaces
. The idea
was to introduce a number of color spaces that would be ideal for image
editing and archiving, which would not be based on any individual input
or output device. Prior to Adobe Photoshop 5.0's use of editing spaces,
users who wanted a color space that filled the task of being device-
independent had to edit in LAB. LAB isn't a very intuitive color space
in which to edit documents and has some significant downsides (see the
sidebar, “Editing in LAB”). Adobe soon began to look at synthetic RGB
spaces that were well behaved for editing documents. I discussed the idea
of synthetic spaces in Chapter 1. These spaces are mathematical con-
structs, a term for a color space that's built using numeric values and not
based on the behavior of any specific, real-world device.
An editing space that is highly device-dependent is sure to change.
This guarantees that the same numbers viewed today likely will appear
different tomorrow or a month from now. Synthetic color spaces don't
have this problem. The values used to produce a synthetic color space
are the same today and a year from now. These color spaces don't have
any of the idiosyncrasies of a physical device like a display. The editing
spaces based purely on a synthetic color space were totally free and inde-
pendent of any physical device. This allowed Adobe to provide color
spaces that in many ways had the advantages of LAB but with the ease
and benefits of an RGB color space. The results are what is called an
RGB
Working Space
; a new concept for most users.
We will look at some of the RGB working spaces in detail and look at
their various advantages and disadvantages. What is important to under-
stand is that instead of working in an RGB color space from a scanner,
digital camera, printer, or actual display, RGB working spaces were
created for editing images. These RGB working spaces allow users to then
convert to any additional color space they want for their intended output
needs. This also allows users to more easily share and view images in a
consistent fashion due to these standardized editing spaces. Users can
convert their original data into a working space and embed that profile
into the file, to define those numbers. The display profile and Photoshop's
Display Using Monitor Compensation architecture provide users the
ability to edit and preview images identically on any properly configured
copy of Photoshop.
