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
The horizontal axis represents the original input brightness and the vertical axis represents the enhanced brightness. Values on either scale range from 0 to 255.
As shown in the figure below, if the curve is changed into a convex shape above the original diagonal, the enhanced image will be brighter than the original.
Normal
Image
Lightened
Image
6
