The GNU Image Manipulation Program (GIMP) is a powerful tool that can be used to create, alter, manipulate, and enhance digital image files — photographs, scanned images, computer-generated images, and more. This section offers a quick overview of The GIMP and refers you to comprehensive references for learning more about it.
To use The GIMP, you will need to know some of the basics. Start The GIMP from the desktop by clicking the Main Menu button and choosing Graphics > The GIMP (from the shell prompt, you can start GIMP by typing gimp).
Figure 15-5 shows a typical GIMP session.
Figure 15-5. The GIMP in Action
To load an existing file, choose File > Open. You will see the Load Image dialog, as shown in Figure 15-6.
The Load Image dialog displays your working directory — the directory you were in when The GIMP was launched. You can navigate up and down the file system tree by double-clicking on the Directories list on the left, then selecting a file to open from the Files list on the right.
Figure 15-6. The Load Image Dialog
File name completion is supported by The GIMP. If you type the first letter (or more) of a file name into the Selection field and press the Tab key, the view will change to only those subdirectories and/or files beginning with that letter or letters.
The file you select will appear in the Selection field near the bottom of the dialog. A thumbnail preview will be displayed on the dialog; alternatively, you will see a Generate Preview button. If you want to see a thumbnail of the image, click the Generate Preview button.
After you have selected a file, click the OK button to open it. You can also double-click a file name to open it.
To save an image file, right-click on the image and choose File > Save (or Save as).
You will see the Save Image dialog if you choose Save as or if you choose Save and the file has not been saved before.
The Save Image dialog looks almost exactly like the Load Image dialog and navigation of the file system tree and choosing files works in the same way.
When you are saving an image, you will need to choose an image format. The GIMP supports a wide variety of image formats, including .gif, .png, .jpg, and .bmp.
Like many applications, The GIMP provides more than one method to accomplish tasks. The easiest way to work with images is to right-click on the image, which will display a set of menus containing most of The GIMP's many capabilities, including image sizing, rotation, and filter application.
For example, imagine you have a picture that you would like to modify to make it look as if it were clipped from a newspaper. To do this, right-click on the image and select Filters > Distorts > Newsprint . . . . Select the quantity of lines per inch using the sliders. When you reach a desired quantity and are ready to render the image, click OK. The GIMP will then render the image with the new effect applied. Figure 15-7 shows an example of an image after the Newsprint filter has been applied.
Figure 15-7. An Image Modified with a GIMP Filter
The Toolbox (Figure 15-8) also has several easily accessible functions. Using the Toolbox you can add text to images, erase regions of an image, or even fill selected regions with the color of your choice.
Figure 15-8. The GIMP Toolbox
For example, if you wish to add text to a file, select the Text button and click on your image. This will load the Text Tool dialog box, where you can choose a font and type some text in the provided text box. Click OK and your text will be displayed as a floating section on the image. You can then move the text to the position you wish using the Move Layers tool. Figure 15-9 shows a photo with exciting new text.
Figure 15-9. Using the Text Tool on an Image
As you can see, The GIMP is a powerful imaging tool, and it takes some time to master all of the functions. Try exploring some of the options yourself. If you make a mistake, don't worry. You can always undo your mistakes by right-clicking on the image and choosing Edit > Undo.
While this chapter covers several applications briefly, there is so much more you can do with them. Refer to the following resources if you are interested in learning more about the applications in this chapter.
The Web has several sites of interest if you are looking for more detailed information about an application covered in this chapter:
http://gqview.sourceforge.net — The official GQview home page.
http://www.gimp.org/ — The official GIMP website.
http://www.rru.com/~meo/gimp/faq-user.html — A Frequently Asked Questions (FAQ) list for questions commonly asked about The GIMP by GIMP users (as opposed to developers).
http://manual.gimp.org/manual/ — The GIMP User Manual website.
http://gimp-savvy.com/ — The companion website to the book Grokking the GIMP by Carey Bunks (New Riders Publishing). The entire book is also available on the site for download!
http://tigert.gimp.org/gimp/ — The GIMP website of tigert (Tuomas Kuosmanen).
Some applications discussed have online documentation included with the package, accessible right from your PC.
For more information about using GQview, refer to the documentation in /usr/share/doc/gqview-version-number/README (where version-number is the version of GQview installed on your system).
The GIMP manual page contains some of the more advanced command-line options and environment variables associated with it. You can read the manual page by typing man gimp at a shell prompt.
If you need in-depth information about the many capabilities of The GIMP, try your favorite bookstore. The following books were available at the time of this writing:
GIMP for Linux Bible by Stephanie Cottrell Bryant, et al (John Wiley and Sons Publishing)
Grokking the GIMP by Carey Bunks (New Riders Publishing)
The Artists' Guide to the GIMP by Michael J. Hammel; Frank Kasper and Associates, Inc.