Do it with the GIMPLUT (Look-Up Tables Effects)Brightness and ContrastDemonstration

3.1.2. Demonstration

Demo

  1. Open lena.png.
  2. Show its histogram ( <Image> -> Image -> "Histogram..." )
  3. Close the histogram.
  4. Access the Brightness and Contrast dialog ( <Image> - Image -> Colors -> "Brightness-Contrast..." )
  5. Modify the Brightness and Contrast in some way.

    Note: the entire modified image is displayed in real-time because Brightness and Contrast changes are so easy to calculate.
  6. Open the Histogram dialog again to show its affects.
  7. Repeat if needed.

Written by Shlomi Fish