The Basics Features of GIMP

After you’ve started GIMP (and assigned it a virtual desktop), you can load an image by selecting File -> Open. The browser dialog box offers a preview facility on the right side of the window.

You will probably need to resize the image window so that it fits within the remainder of the screen. You can then use the Zoom tool to ensure that the image fills the editing window, which will make working with it much easier. Alternatively, you can click the Zoom drop-down list in the lower-left of the image window. You can save any changes you make to an image by right-clicking it and selecting File -> Save As. You can also print the image from the same menu. Before you begin editing with GIMP, you need to be aware of some essential concepts that are vital to understand in order to get the most from the program:

Copy, cut, and paste buffers: Unlike some Windows programs, GIMP lets you cut or copy many selections from the image and store them for use later. It refers to these saved selections as buffers, and each must be given a name for future reference. A new buffer is created by selecting an area using any of the selection tools, then right-clicking within the selection area and selecting Edit -> Buffer -> Copy Named (or Cut Named). Pasting a buffer back is a matter of right-clicking the image and selecting Edit -> Buffer -> Paste Named.

Paths: GIMP paths are not necessarily the same as selection areas, although it’s nearly always possible to convert a selection into a path and vice versa (right-click within the selection or path, and look for the relevant option on the Select menu: Select -> To
Path or Select -> From Path). In general, paths allow the creation of complex shapes, rather than the simple geometric shapes offered by the selection tools. You can also be more intricate in your selections. Paths can be saved for later use. To view the Paths dialog box, right-click the image and select Dialogs -> Paths.

Layers: In GIMP (along with most other image-editing programs), layers are like transparent sheets of plastic that are placed on top of the image. Anything can be drawn on each individual transparent sheet, and many layers can be overlaid in order to create a complicated image. Layers also let you cut and paste parts of the image between them. It’s also possible to apply effects and transformations to a single layer, rather than to the entire image. The Layers dialog box, appears by default, but if you closed it earlier, you can open it again by right-clicking the image and selecting Dialogs -> Layers. The layers can be reordered by clicking and dragging them in the dialog box. In addition, the blending mode of each layer can be altered. This refers to how it interacts with the layer below it. For example, its opacity can be changed so that it appears semitransparent, thereby showing the contents of the layer beneath.

Source of Information : Apress Beginning Ubuntu Linux 3rd Edition