7. The Menus / 7.7 The Filter Menu

7.7.21 Quality/Optimize Contrast

This function optimizes the contrast in that way, that the image will have the highest possible contrast. Using the function on normal images the effect may be to extreme. If it is so, you can reduce it by using Intensity.

You can also specify how the selection is handled. If Equalize selected area only is activated, the function only edits the selected area. Otherwise, it uses the selected area to determine how the image should be optimized and then edits the entire image.