GIMP 2.8.3 review
GIMP (the GNU Image Manipulation Program) is one of those programs that many of the geekier Mac OS X users are aware of. Essentially Gimp is an open-source re-creation of Adobe Photoshop, this means that it's community built and managed and you can download it for free.
The good news is that since GIMP 2.8.2, it no longer needs the X11 environment and now runs as a native Mac OS X app. Installation is as simple as downloading a build, and double clicking. And without X11 in the way it now has a typical Menu bar structure, so it's much more instantly familiar to regular users.
GIMP has previously only been available inside the X11 environment (another thing that many people aren't aware of). X11 provides Mac OS X with a separate GUI for running Linux and Unix software. This meant that although you coud run GIMP it didn't have the same Aqua interface that Mac OS X applications have (specifically it didn't have the Menu bar at the top of the screen). This, along with the general faff of having to install X11 first restricted GIMP to the more 'enthusiastic' spectrum of computer users.
So, all well and good, but can a group of enthusiasts really create a valid alternative to Adobe Photoshop? Well the GIMP team have gone a long way to narrowing the edge between the two programs, and running inside Mac OS X without the X11 abstraction layer makes a lot of difference.
The GIMP interface vs Photoshop
Crucially, both GIMP and Adobe Photoshop CS6 have implemented an optional single window mode that pulls together all the floating palettes inside the image window. Between this and the newfound presence of a Menu bar, GIMP has come a long way since version 1 towards replicating Photoshop.
Die-hard Photoshop designers will still find that GIMP's layout is slightly different, and menu options will require some re-learning. Having said that, GIMP is not such a massive jump in interaction from Photoshop that seasoned photo editors won't be able to pick up and use. Also the Adobe Photoshop CS6 interface itself is a fairly radical depature from previous versions.
But there's no denying that GIMP lacks the slickness of Photoshop. One fairly obvious example would be the Crop tool. Adobe implemented persistant drag handles to images that enable you to instantly crop (or even expand) an image at any time (in a manner reminiscent of what Apple's being doing with iPhoto in iOS). In GIMP you still have to use the separate Crop tool and draw a box around an image. There are other subtler differences too, such as the icons which have less uniform colour than Photoshop and dialog boxes that are more obtuse. In general it has that 'open source' feel that you wouldn't get from a company like Adobe.
The GIMP interface (left) and Adobe Photoshop CS6 interface (right)
GIMP vs Photoshop: Max OS X performance
We opened up GIMP and Photoshop side by side and took a look at Activity Monitor. It turns out that Photoshop uses 329 MB whereas GIMP uses 269.7 MB. The test machine is an iMac with 12GB RAM so there's plenty of give in the system, but it should mean that GIMP is more efficient on low RAM machines.
Having said that we found that Adobe Photoshop CS6 launched faster (17.56 secs) than GIMP 2.8.3 (24.53 secs). So it may be that that code is more efficient. We've certainly found CS6 an improvement on earlier versions. It's fair to say that both pieces of software perform much more efficiently than either previous incarnations.
GIMP vs Photoshop: feature set
Neither Photoshop CS6 or GIMP are taxing modern computers to the level of 3D or image animation software (see Adobe CS6 After Effects review), so we think it's the interface and feature set that will probably make the difference to your average designer.
The good news is that GIMP now has layer groups. The lack of these previously made working in GIMP something of a nightmare for professional designers working with multiple layered images.
The bad news is that it still lacks decent batch support in the form of actions. You can batch process images but it has to be done through the command line using a scripting language, so get ready to learn UNIX. Most designers need something a little more accessible than this.
GIMP also doesn't support CMYK out of the box. instead you need to install a separate CMYK package using makepkg. CMYK support is apparently fairly low down the list of features that GIMP are due to implement, and it's fair to say that only people involved in DTP (desktop publishing) are truly interested in the CMYK colour space. Although for them it's a deal-breaker. GIMP can open images saved in CMYK space but converts them immediately to RGB.
The native file format for GIMP is .xcf, and although you can export to other formats (JPG, PNG and so on), this is the format that GIMP saves and works in. And it's not compatible with Photoshop, InDesign, any standard Apple program (iPhoto, iMovie and so on). Photoshop can save to a variety of different file formats, and the default .psd file is compatible with other Adobe and Apple software.
Aside from that we also encountered the odd gremlin in GIMP, like errors when tyring to open multi-layered grouped PSD files (these were files that we used to create a recent corporate presentation).
The GIMP Price issue
So GIMP still isn't perfect, although many of its imperfections are niggles in the face of all that it offers. If you're a web designer you're unlikely to require batch actions, CMYK support, or cross compatibility with other video and image management software.
Then there's the price. GIMP is free, and now it's easy to install and use. Adobe Photoshop CS6 costs £667.20 for the full UK license (or you can pay £17.58 per month as part of Creative Cloud). It's worth noting that for somebody who works professionally as an image editor, paying £667 for Photoshop CS6 (or £1,238 for Creative Suite Design Standard) isn't actually a bad investment. The whole Macworld team runs on Adobe software. But if you're an hobbyist photographer or designer then there's a big difference between £667 and free; and that difference in price is much larger than the difference in feature set between the two programs.
Having said that, if you're more of an image dabbler that doesn't want to outlay such a vast amount, there's Pixelmator, which is £10.49 from the App Store and offers the same sort of feature set as GIMP and Photoshop but with a vastly nicer interface.
But let's not take away what GIMP has achieved here, it's taken a few years but they've managed to re-create most of Adobe Photoshop for free and finally got it working inside the Mac OS X interface natively. It's a powerful image editing program and all yours for free.
GIMP is much better now that it's running inside Mac OS X without the need of X11, and it offers a wide range of features for the price (which is nothing). But there's no getting away from the fact that it falls short of Adobe Photoshop CS6, and isn't anywhere as near as slick as Pixelmator. Mind you: it's free.