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Inside the Kernal
Linux Graphics and Imaging Apps
You can use graphics and imaging applications with Linux to work with images and graphics (line drawings and shapes). This month, we will take a look at two.

by Emmett Dulaney

9/22/2010 -- You can use graphics and imaging applications with Linux to work with images and graphics (line drawings and shapes). Two of the most popular of these applications are:

  • The GIMP (GNU Image Manipulation Program): A program for viewing and performing image manipulation tasks, such as photo retouching, image composition and image creation.
  • GNOME Ghostview (GGv): A graphical application capable of displaying PostScript files.

This month, we will take a look at each of these.

The GIMP
The GIMP is an image manipulation program written by Peter Mattis and Spencer Kimball and released under the GNU General Public License (GPL). Most Linux distributions come with this program, although you may have to specifically select a package to install it. The GIMP is comparable to other image manipulation programs, such as Adobe Photoshop and Corel PHOTO-PAINT.

To try out The GIMP, look for it under the Graphics category in the main menu. When you start The GIMP, it displays a window with copyright and license information. Click the Continue button to proceed with the installation. The next screen shows the directories to be created when you proceed with a personal installation of The GIMP. NOTE: If you can't find The GIMP under the Graphics category, choose Add/Remove Software from the System Settings menu and install it from there.

The GIMP installation involves creating a directory in your home directory and placing a number of files there. This directory essentially holds information about any changes to user preferences you may make to The GIMP. Go ahead and click the Continue button at the bottom of the window. The GIMP creates the necessary directories, copies the necessary files to those directories, and guides you through a series of dialog boxes to complete the installation.

When the installation is finished, click the Continue button. The GIMP then loads any plug-ins. It displays a startup window that shows a message about each plug-in as it loads. After finishing the startup, The GIMP displays a tip of the day in a window. You can browse the tips and click the Close button to close the Tip window. At the same time, The GIMP displays a number of other windows, including a main navigation window titled The GIMP, a Toolbox window (usually on the left side), a Brush Selection window and a Layers, Channels, Paths window. The center navigation window gives you access to new images to work with, image editing functions and a number of effect filters that you can apply to the image. The Toolbox window lets you quickly select a number of important image manipulation tools.

To open an image file in The GIMP, choose File, then Open. The Load Image dialog box appears. You can change directories and select the image file that you want to open. The GIMP can read all common image file formats, such as GIF, JPEG, TIFF, PCX, BMP, PNG, and PostScript. After you select the file and click OK, The GIMP loads the image into a new window.

The Toolbox window has many buttons that represent the tools you use to edit the image and apply special effects. You can get pop-up help on each tool button by placing the mouse pointer over the button. You can select a tool by clicking the tool button, and you can apply that tool's effects to the image to see what it does.

When you right-click the image window, The GIMP displays a pop-up menu that has most of the options from the GIMP's top toolbar.

You can do much more than just load and view images with The GIMP, but a complete discussion of all its features is beyond the scope of this book. If you want to try the other features of The GIMP, consult The GIMP User Manual (GUM). You can also choose Help, then GIMP Online, and User Manual Web site to access the online documentation for The GIMP.

Visit The GIMP home page at http://www.gimp.org to find the latest news about The GIMP as well as links to other resources.

GNOME Ghostview
GNOME Ghostview is a graphical application ideal for viewing and printing PostScript or PDF documents. For a long document, you can view and print selected pages. You can also view the document at various levels of magnification by zooming in or out.

To run GNOME Ghostview in Fedora, choose Graphics, then PostScript Viewer from GUI desktop. The GNOME Ghostview application window appears. In addition to the menu bar and toolbar along the top edge, a vertical divide splits the main display area of the window into two parts.

To load and view a PostScript document in GNOME Ghostview, choose File, then Open, or click the Open icon on the toolbar. GNOME Ghostview displays a File-Selection dialog box. Use this dialog box to navigate the file system and select a PostScript file. For example, select the file tiger.ps in the /usr/share/ghostscript-8.64/examples directory. (Use your system's version number of Ghostscript in place of 8.64).

To open the selected file, click the Open File button in the File-Selection dialog box. GNOME Ghostview opens the selected file, processes its contents and displays the output in its window.

REMEMBER: GNOME Ghostview is useful for viewing various kinds of documents that come in PostScript format. (These files typically have the .ps extension.) You can also open PDF files (which typically have .pdf extensions) in GNOME Ghostview.


Emmett Dulaney is the author of several books on Linux, Unix and certification. He can be reached at .

 

 

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