GIMP Is No Lame Photo Tool
Apr 14, 2010 5:00 AM PT
The Linux world is filled with numerous capable packages for just about every computing category. Graphics manipulation applications are no exception. In any list of able-bodied graphics candidates, GIMP 2.6 should be one of the top three contenders.
GIMP is Linux Speak for GNU Image Manipulation Program. It is a free powerhouse that sets the standard for displaying and tweaking all things photographic on a computer screen. It is a very close first cousin to the not-so-open-source program known as Adobe's Photoshop.
In the high-end category of graphic manipulation apps, GIMP is one of a few high-caliber players. Programs in this high-performance class are not photo cataloging viewers the likes of Google's Picasa. They are advanced photo manipulation and retouching tools.
One such app in this classification is xv, a shareware interactive image manipulation program for the X Window System. Another is Photogenics, a graphics package for creating images from scratch or by modifying existing pictures. Also in this group is the free ImageMagick, a collection of tools for image conversion, annotation, composition, animation and montage creation in over 87 major image formats.
When I left Microsoft Windows for the Linux platform, I desperately needed an inexpensive replacement for Photoshop. One of the first photo editing apps I encountered was GIMP. It is available in most Linux package management systems. Its tool set has all the bells and whistles I used in the Adobe product.
GIMP became my de facto benchmark measurement for similar photoshopping apps. The fact that GIMP runs on both of my Linux workhorse distros -- Ubuntu and Puppy Linux -- made using it a real bargain.
I especially like GIMP's module-based, customizable interface. For example, I can change themes, colors, spacings and icon sizes. The dockable modules let me stack them into tabs or float them freestyle in their own open windows.
Perhaps one of GIMP's best features is the extensive preferences panel. There I can set my defaults for environment options like resource consumption and image thumbnail size along with Tool Options and display parameters. These individualized settings come in very handy when working with photos on my netbook. I love the do-it-my-way choices.
GIMP comes with a learning curve. If you are unfamiliar with photo manipulation packages in general, any of the top-notch photo editing programs will be intimidating at first. But GIMP gives even those with a working knowledge of graphics editing a bit of a challenge.
One reason for this is the sheer number of options available in the drop-down menus. You can spend an hour or two playing around with the choices found in the Image, Layer, Colors, Tools and Filter menus alone.
I recommend leaving the hints option engaged. When you hover the pointer over a menu item, a bubble opens telling you what that option does. Of course, you can always click on a selection and then resort to the Undo option in the Edit menu to get the picture back to where it was before you messed it up.
Using the modular design of GIMP takes some getting used to. When you open the program, a vertical Toolbox panel opens on the left edge of the screen. Near the top center of the screen is a blank viewing window. Of course, since these are unattached elements, you can resize and drag them anywhere you want on the monitor.
However, once you open an image, this viewing window fills nearly all of the remaining screen real estate. This photo window is fully movable and resizable. It remains detached from the toolbox panel. The toolbox contains icons and check boxes for numerous editing commands. The main viewing window contains all of the drop-down menus.
As mentioned earlier, under the Windows menu are options to pull out various menus so you can dock them elsewhere on the screen. This gives you the ability to localize and customize particular tools you use all the time in various photo editing sessions.
GIMP handles more than three dozen file formats. These range from the common formats such as JPEG, GIF, PNG and TIFF to special-use formats such as the multi-resolution and multi-color-depth Windows icon files. GIMP's plug-in architecture lets you extend format capabilities.
By loading a file of one format and saving it as another format, file conversions are easily handled. The list of possibilities includes Encapsulated PostScript Image (.epa), AutoDesk FLIC anjimation (.flc), Photoshop Image (.psd) and Alias Pix Image (.pix, .matte).
Making a format conversation involves clicking on the File Type by Extension menu in the File saving panel. It doesn't get any easier than that. Of course, other photo viewing apps let you change file formats. But having this option in GIMP just makes the app much more useful.
I also like how GIMP integrates file compression features to save space. Any format can be saved with an archive extension such as ZIP, GZ or BZ2. GIMP transparently compresses the file without any extra steps. This eliminates having to save the graphic file and then load an archiving tool to compress it.
That's pretty slick. It's also pretty handy. Numerous times each day I shuttle photo files onto thumb drives or attach them to emails.
Tricks and Tips
The real power of GIMP lies in its ability to enhance photos and other graphic files. I am what you might call a very imprecise photographer. Graphics files are often a necessary evil to my journalism work. Maintaining the exhaustive family photo albums is a time consuming labor of love as well.
To be blunt, I mostly point and shoot. What looks good in a tiny digital camera viewing window is often not nearly as good when viewed on a big screen. So file editing is as critical to me as is editing a text file.
GIMP's transformation toolsets go a long way in fixing photo flaws such as perspective distortion caused by lens tilt. Ditto for fixing lens barrel distortion. Particularly handy is the channel mixer. It is a great boon to touching up B/W photography.
GIMP has tools for advanced photo retouching techniques. It is easy to remove unnecessary details with the clone tool. Touching up minor details is a snap with the new healing tool added to this current version of GIMP.
Be sure to check out the freehand select tool with its support for polygonal selections. It lets you mix free hand segments with polygonal segments. You can also edit existing segments by applying angle-constraints to segments and use the normal selection tool operations to add and remove elements.
Brush dynamics is an awesome tool. You can map different brush parameters to pressure, velocity and random. The velocity and random settings are applied with a mouse. The Ink tool handles velocity-dependent painting much better than earlier versions of GIMP.
With Brush dynamics you can let GIMP handle your brush stroke. GIMP regulates brush pressure and velocity so they vary along the length of the stroke. Pressure starts with zero, increases to full pressure and then returns to no pressure. Velocity starts from zero and goes to full speed by the end of the stroke.
Whether you are a consumate photographer or are all thumbs on the shutter switch, GIMP can mend a fistful of picture-taking ills enable extensive artistic touches to any photograph. It is an indispensable graphic manipulation app.
It is far superior to other graphic editing tools. Use it to get the kinks out of your digital pictures. Then use another app to catalog and display your photo albums. The view will be so much better.