Tonal Map
If you select the Tonal Map tab, the following will be displayed.
Tonal Map tab
The Tonal Map is yet another way to adjust Highlight, Midtone, or Shadow levels in your images. When you open the Tonal Map dialog box, a tonal map consisting of a diagonally straight line appears. Notice that at every point on the default tonal map, the output shadow, midtone, and highlight brightness levels are equal to the input shadow, midtone, and highlight brightness levels.
