5.4.  Brightness-Contrast tool

Revision History
Revision $Revision: 2554 $ 2008-01-16 j.h

The Brightness-Contrast tool adjusts the brightness and contrast levels for the active layer or selection. This tool is easy to use, but relatively unsophisticated. The Levels and Curve tools allow you to make the same types of adjustments, but also give you the ability to treat bright colors differently from darker colors. Generally speaking, the BC tool is great for doing a "quick and dirty" adjustment in a few seconds, but if the image is important and you want it to look as good as possible, you will use one of the other tools.

In GIMP 2.4, a new way of operating this tool has been added: by clicking the mouse inside the image, and dragging while keeping the left mouse button down. Moving the mouse vertically changes the brightness; moving horizontally changes the contrast. When you are satisfied with the result, you can either press the "OK" button on the dialog, or hit the Return key on your keyboard.

5.4.1.  Activate the Tool

You can get to the Brightness-Contrast tool in two ways :

  • In the the image-menu through: ToolsColor ToolsBrightness-Contrast or ColorsBrightness-Contrast,

  • by clicking the tool icon: in Toolbox, provided that you have installed color tools in Toolbox. For this, go to Tools Dialog.

5.4.2.  Options

Figure 13.122.  Brightness-Contrast options dialog

Brightness-Contrast options dialog


This slider sets a negative (to darken) or positive (to brighten) value for the brightness, decreasing or increasing bright tones.


This slider sets a negative (to decrease) or positive (to increase) value for the contrast.


The Preview check-box makes all changes to the brightness and contrast dynamically so that the new level settings can be viewed immediately.