Design : Gimp : Normalise Exposure

Correcting Over & Under Exposed Images

If you have an image where some areas are over exposed and others under exposed then you can use this technique to help correct them.

Open the image in the Gimp .

First we need to duplicate the original layer:
Layer >> Duplicate Layer

Duplicate Layer

With the duplicate layer selected we need to remove all the colour:
Colours>> Desaturate...

Colours Desaturate

Choose Average

Desaturate

Invert the light and dark areas:
Colours>> Invert.

Colours Invert

We need to be able to see the original layer through the duplicate layer:
Change the duplicate Layer Mode from Normal to Overlay.

Mode Overlay

Finally, we need to make the duplicate layer have less of a cartoon effect on the image and sharpen (via Blur) the image lines:
Filters>> Blur>> Gausian Blur.

Blur Gaussian

This sharpens the image again by blurring the mask of light you have just created, play around with how much, sometimes very high/very low works best depending on the image.

Gaussian Blur Settings

Your image may not be perfect but it should be a lot more viewable/pleasing to the eye. Play around with the settings to create the best effect.