Samsung SF-4500 User Manual page 191

Tonal Map
If you select the Tonal Map, the following dialog box 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.
The shape and slant of the Tonal Map represent brightness level ratios
between the input of the original image and the output image data. By
clicking on the Tonal Map line, a hand-shaped cursor will appear which can
be dragged in such a way as to alter the shape of the tonal map line. The
horizontal axis represents the original input brightness and the vertical axis
represents the enhanced brightness. Values of either scale range from 0 to
255.
If you deform the curve into a convex shape (above the original diagonal),
the enhanced image will be brighter than the original.
Normal Image Lightened Image
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