Gimp vs. Photoshop
Let me explain why I am writing this: frustration with the Gimp. This means I am biasaed. Before I even start, Photoshop has won (and by quite some margin). In fact, this isn’t a contest, it is a list of things that I don’t really like with the Gimp. As always with this kind of article, it is my own very personal opinion that I am offering here, and I’d be interested to hear where you disagree.
For my comparison I am using Windows XP, mainly because I don’t like Photoshop with Wine and also because I don’t own a Mac anymore (though I fully intend to replace my current computers with Macs when they are ready for replacement).
Interface
Photoshop uses an MDI Window to keep all Photoshop-related windows together. This isn’t my favourite style of application presentation, but it beats the alternative that Gimp provides. The Gimp has windows strewn everywhere, and it feels chaotic. It clutters your task bar unlike any other programme I have ever used.
Photoshop has a very narrow toolbox that sits on the left hand edge of the screen. This isn’t a Photoshop invention – Deluxe Paint on the Amiga had a similar setup back in 1989, as do many other paint and DTP packages. They do this for a very good reason: it is very narrow so as to not distract or get in the way.
The same criticism can be applied to other palettes in the Gimp – they are big, clumsy, and feature far too much clutter. They don’t dock and snap like Photoshop’s palettes and they don’t minimise out of the way for anybody (unless you close them, but then you can’t get them back so easily).
Quality of Alogrithms
Today I wrote a blog article that required screen captures. I used the Gimp. I saved the images as GIFs – the bulk of each screen capture consisted of 4 colours at most.
The Gimp did an appalling job of converting the images to an indexed palette – it dithered the huge swathes of solid colour for no good reason whatsoever. Photoshop would never make such an elementary mistake.
I decided that maybe you need to manually convert from RGB to Indexed for best results, so I changed the image format in the Image menu. I noticed the Dithering options and got suspicious: the default is Floyd-Steinberg. Hmmm, a nice matrix operation, you say?
If you use ‘no dithering’ it works perfectly well for simple images. More complex images (photos etc) may not work as well, but who saves photos as GIF anyway? That said, for subtle gradients Floyd-Steinberg still came out worst – another filter ‘positioned’ worked best in those cases.
More problems with filters
It isn’t just the GIF filter that is a bit poor. The blur filters are a bit rubbish too. I am sure that they, like the GIF colour reduction code, are also based on matrix maths invented in the 1970’s.
The first time I ran a blur filter in the Gimp I almost burst out laughing at the damage it had done to the image’s data. I haven’t spent long enough working out why this was so, and I might be judging unfairly harsh – I shall investigate further.
Save Dialog
What else? Well, the save dialog isn’t great. I know Photoshop can make you jump through hoops, but the interface is very consistent and, once used to it, the Save for Web window can be a great help (previewing different compressions in realtime is excellent).
The Gimp uses a custom-written save window unlike any other that you’ve ever seen. It’s OK when you’re used to it, as long as you only want to save to one of a handful of locations. You can browse folders, but it’s a bit of a mess from a usability point of view.
To specificy your preferences for the image format you must supply an filename extension. How very Microsoft. It then pops up a Window warning you about any loss of quality that might occur as a result of your choice. That’s OK, and to be expected. Photoshop does something similar if you ‘Save’ an image as GIF (rather than export it). Once you accept that quality is going to suffer, you are presented with another, totally pointless window that lets you enter a comment and some other stuff. Why this window can’t be disabled I don’t know. It’s annoying.
I’d also like to have the option of a regular Windows save dialog because that’s what works well in a Windows environment.
Selections
Selection areas are a wonderful tool. You can create a selection, carefully position it, round it, apply stroke, shrink it, apply fill and so on and so on, gradually building up an image. It is a mainstay of much design work.
In the Gimp, certain selection dialogs (stroke and fill in particular) are a bit lacking, though they are usable enough.
What was really annoying me was that I couldn’t ‘move’ the selection – or rather, I could move the selection, but it also moved the image contained within the selection. For a long time I couldn’t find a way around this – even using ‘spare’ layers and hiding the layer that contained the image didn’t work—it still moved the hidden layer! You can’t lock layers, so far as I can tell.
Playing with the add/subtract selection keys (shift, ctrl, alt) I discovered that holding alt while moving a selection moved just the selection. Photoshop has two tools for the two jobs, and I think it works better.
The add/subtract selection tools (shift and ctrl) are broken because those keys also double up as ‘make square’ and ‘grow from center’ – both useful tools, but not neccessarily what you wanted. If you press shift before dragging the selection, it should simply add to the existing selection. If you press shift when you’ve already started making the selection it should make it square. The problem is that in the first case it also makes it square.
Closing thoughts
Despite my grumbling I do actually like the Gimp. It is Free and Open, so theoretically I could fix these problems myself. I would dearly love to have the time to give the interface a complete overhaul, but I think it is so intrinsicly linked to GTK that a complete re-write would be easier.
Unfortunately, for now at least, I have no chance of finding any time for this kind of endeavour. Maybe one day.
Update: The Gimp team have launched an effort to improve the GUI. They have a website, http://gui.gimp.org, and are accepting ideas and applciation-screen mock-ups. We will be sure to add our ideas. Hopefully the Gimp will soon become a very usable and professional tool.
