Adjusting Color Levels - Novell LINUX ENTERPRISE DESKTOP 11 - APPLICATION GUIDE 17-03-2009 Application Manual

Retouching Images—The Clone Tool
The clone tool is ideal for retouching images. It enables you to paint in an image using
information from another part of the image. If desired, it can instead take information
from a pattern.
When retouching, it is usually a good idea to use a small brush with soft edges. In this
way, the modifications can blend better with the original image.
To select the source point in the image, press and hold Ctrl while clicking the desired
source point. Then paint with the tool as usual. When you move the cursor while
painting, the source point, marked by a cross, moves as well. If the Alignment is set to
None (the default setting), the source resets to the original when you release the left
mouse button.

20.5.4 Adjusting Color Levels

Images often need a little adjusting to get ideal print or display results. In many programs
designed for inexperienced users, the brightness and contrast levels are modified. This
can work and is also available in The GIMP, but better results can be obtained by ad-
justing the color levels.
To do this, select Colors > Levels. A dialog opens for controlling the levels in the image.
Good results can usually be obtained by clicking Auto. To make manual adjustments
to all channels, use the dropper tools in All Channels to pick areas in the image that
should be black, neutral gray, and white.
To modify a channel individually, select the desired channel in Channel. Then drag the
black, white, and middle markers in the slider in Input Levels. Alternatively, use the
dropper tools to select points in the image that should serve as the white, black, and
gray points for that channel.
If Preview is checked, the image window shows a preview of how the image would
look with the modifications applied. When the desired result is achieved, press OK to
apply the changes. With Reset, restore the original settings. Cancel aborts level adjust-
ment.
Manipulating Graphics with The GIMP 217