Graphic categories and the GIMP
Being able to express yourself with a graphical aid can be the difference between a bored audience and a receptive one. There is a wide range of open source graphical software available, and as packages have evolved, to add new features, many spill over into several categories, so its important you select the right package for the job.
Graphic applications can be divided into a number of different categories, one such categorisation is shown below. While there are features which may be specific to a particular category, many of the basic tools overlap. For example being able to crop and resize an image, is a feature found in most aspects of graphic image manipulation primary advantage offered by computers is precision, so the first graphics packages were concerned with technical drawings. CAD packages today are highly specialised, and although not originally designed to be art tools many have evolved and spread into this category. At their heart is vector graphics.
- Art and Graphic design – Drawing, Illustrations and desktop publishing
Inkscape is an open source alternative to CoralDraw and Adobe Illustrator and is based on the W3C scalable vector graphics (SVG) standard. Scribus provides a desktop publishing capability. Many illustration packages are page orientated to produce striking full colour posters. Features include good text handling and eye catching special effects. For commercial printing it must be possible to colour separate your drawing.
- Photo editing e.g. GIMP. The GIMP is the open source equivalent of (Adobe) Photoshop, the commercial brand leader. The GIMP has a plug-in extension called GAP (graphic animation package) which extends the basic functionality provided for animation.
- Animation (both 2D and 3D)
For 3D grahics and animation, Blender is probably the most obvious choice, however you may find working in 3D initially rather daunting.
- Business Presentations
e.g. Libre Office Draw, or Libre Office impress.
- Technical drawings (CAD both 2D and 3D
e.g Librecad, openCASCADE and pythoncad. There are fewer open source packages in this category to rival the commercial brand leader, (Adobe) AutoCAD.
There are a number of graphics programs available for Linux, but by far, the most technically advanced and capable is the GIMP (GNU Image Manipulation Program – sometimes referred to incorrectly as Graphic Image Manipulation Program). The GIMP is pre-packaged with all the major Linux distributions (distros), although you should be aware, it may not be the latest version included in your particular distro. At the time of writing, the most recent version was 2.8.6 released on the 21st June 2013.
It is the GIMP that we propose to focus on throughout these pages, especially as it embraces a number of the different graphic categories listed above, from photo editing, art and design through to 2D animation . Many of the tools can be used across the board, others maybe more suited to art and design for example. If you look under the GIMP tools menu, you see tools that have a similar function, have been grouped together, and loosely reflect the context in which they might be used. Artists therefore will probably make more use of the paint tools, than say a photographer.
If you’ve used Adobe Photoshop in the past, you’ll already be somewhat familiar with how the GIMP works. Nevertheless, there are differences. It has a pallet of tools, fully supports multiple layers, transparencies and a huge amount more. In addition, it can be supplemented with plugins, that are mostly free. But a few plugins are also commercially available for purchase.
These notes aim to illustrate some of the different ways in which the GIMP can be used. The examples shown under this section, are (loosely) arranged by graphic category, and show how a combination of different tools and techniques, can be used to produce an end result. This serves to highlight some of the different features and setting that can be used in various contexts.
A set of shorter examples found under the section tools and menus, show the basics of the various tools.