5.4. Brightness-Contrast tool
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. Activating the Tool
You can get to the Brightness-Contrast tool in two ways:
In the the image-menu through:
→ → or
by clicking the tool icon:
in Toolbox, provided that you have installed color tools in Toolbox.
For this, go to
Figure 13.130. Brightness-Contrast options dialog
You can save the color settings of your image by clicking the
button opens a menu:
Figure 13.131. Preset Menu
which lets you Import Settings from File or
Export Settings to File,
and gives you access to the Manage Save Settings dialog:
Figure 13.132. Manage saved Settings 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.
Edit these settings as Levels
To make your work easier, this button lets you turn to the
Levels tool with the same
The Preview check-box makes all changes to the brightness and
contrast dynamically so that the new level settings can be viewed