Rendering menu > Video Post > Video Post toolbar > Add Image Filter Event > Choose Contrast Filter from the Filter Plug-In
list.
Rendering menu > Video Post > Video Post window > Select a Contrast Filter. > Video Post toolbar > Edit Current Event > Setup
The Contrast filter allows you to adjust the contrast and brightness of an image.

Contrast—Set the spinner between 0 and 1.0. This compresses or expands the latitude between maximum black and maximum white by creating a 16-bit look-up table for any given gray value in the image. The computation of the gray value depends on whether you select Absolute or Derived.
Brightness—Set the spinner between 0 and 1.0. This increases or decreases all color components (red, green, and blue).
Absolute/Derived—Determines the computation of the gray value for Contrast. Absolute uses the highest value of any of the color components. Derived uses an average of the three color components.