6.7. GEGL Operation

Figure 13.181. GEGL Operation tool

GEGL Operation tool

GEGL (Generic Graphical Library) is a graph based image processing library designed to handle various image processing tasks needed in GIMP.

The GEGL Operation tool has been added in GIMP 2.6 and was originally meant as an useful experimental tool for GIMP developers. The GEGL Operation tool enables applying GEGL operations to the image and gives on-canvas previews of the results.

[Warning] Warning

GEGL is in a very early phase and still under construction.

The GEGL Operation tool is experimental.

6.7.1. Activating the Tool

You can get to this tool only from the image menu: ToolsGEGL Operation.

[Tip] Tip

In addition to this tool for performing special GEGL operations you can configure GIMP to use GEGL for all color operations.

6.7.2. Options

Figure 13.182. GEGL Operation tool options

GEGL Operation tool options

GEGL Operation tool with no operation selected.


Operation

Click on this button to select the operation you want to apply to the active selection or, if there is no selection, to the active layer.

Some of these operations are very basic operations like color which fills the active selection or layer with the specified color, while operations like fractal-explorer produce fairly complex patterns — just like a rendering filter.

Remember that this is an experimental tool, so some operations may not work or even crash GIMP. As a consquence, it doesn't make sense to describe the operations here as long as the GEGL Operation tool is experimental

Operation Settings

The operation settings depend on the selected Operation:

Figure 13.183. Operation Settings example

Operation Settings example

GEGL operation Gaussian Blur selected.


If the options of the selected GEGL operation are not self-explanatory (guess what's the purpose of the color operation's Color option) you can look for a corresponding non-GEGL tool. For example, the Fractal Explorer filter may have the same or similar options as the fractal-explorer operation.

Or you can make use of the nice realtime preview feature and just experiment with different settings.

Preview

If this options is checked, as it is by default, you will get an on-canvas preview of the selected operation as soon as the operation in finished. You will have to press the OK button to actually apply the operation to the image.

The tool buttons

Reset

Pressing this button resets the operation settings the to their defaults.

Cancel

Clicking on this button aborts the GEGL operation tool and leaves your image untouched. This is equivalent to close the dialog window using the usual Close button provided by your window manager.

OK

You have to press this button to apply the selected operation to the image. Then the dialog window will be closed.