Graphics Programs Reference
In-Depth Information
Fig. 1-14
Photoshop's
Curves dialog (top)
illustrates the concept of a
tone response curve. Here
I've pulled a midtone
correction and Photoshop
provides input and output
values based on this tone
correction. The Photoshop's
Levels dialog (bottom)
creates a correction curve
based on the gamma
formula when only the
middle slider is altered.
Moving either the black or
white slider would
introduce a more complex
tone correction, which
would not be based on the
gamma formula.
