Background
As you know, the Mac software market is enjoying something of a deluge of wannabe Photoshop alternatives, generally aimed at the casual user. Adobe has left this market wide open by (a) not lowering its prices, (b) not catering for non-professional image originators (i.e. the “lite” version of Photoshop is aimed squarely at photographers rather than artists), and (c) treating Mac pros as second-class citizens — something they don’t like and aren’t used to in the world of graphics.
Contenders
Pixelmator has the highest profile, Photoline probably has the lowest, and Acorn got in early and received a lot of recognition (awards, etc.). There’s always The GIMP and Adobe’s Photoshop Elements (if you really enjoy being treated like a second-class citizen by Adobe), of course. There’s also Pixel. And then there’s the lamentable Iris (which seems to be going nowhere — it’s still at “1.0” and Nolobe’s forums are still MIA: nothing says crap like an indie developer with no forums, except perhaps an indie developer who used to have forums and then took them down when they filled up with posts about how bad his software sucks).
I reviewed Photoline for MacApper more than a year ago (when it was at version 14.10 or so — it’s since received a major free upgrade (to 14.5x) and a major paid for upgrade (to 15.x). Since then the other major changes are that Pixelmator has received numerous significant (free) updates and become a pretty serious contendor for basic image editing and Photoshop CS4 has been released with little new functionality and no 64-bit support for Mac OS X. Oh, and Pixel 1.0 is — we are told — rapidly approaching its supposed 1.0 release (don’t hold your breath, the last 1.0 beta was in 2006 and was PowerPC only).
A Simple Head-to-Head Comparison
Here’s a simple example of using a single feature in Pixelmator, Photoline, and Acorn which — I think — pretty much underscores everything that I like and dislike about each program in a nutshell. The “zoom blur” function simulates the motion blur effect you see when staring straight ahead at high speed or zooming in really fast. It’s a neat looking effect that brings the centre of the blur effect to fore (since it’s the only thing in focus) and makes even a pretty boring image look quite spiffy. It’s also a feature Photoshop has had (unchanged!) since forever.
In Acorn you get a really neat mechanism for compositing filters (which is of no use at all) but no method of actually setting the center of the blur effect except numerically entering coordinates (which is actually worse than Photoshop’s early 90’s dialog box). Correction: Acorn allows you to disclose a pane which lets you (somewhat clumsily, and in low resolution) drag the effect center graphically. It’s still clearly inferior to Photoline or Pixelmator in this respect, but it’s actually better than Photoshop. (End Correction.)Â Also since Acorn’s way of previewing the effect is to render the whole image (and zoom blur is not much accelerated by using CoreImage) it’s really painful to fine-tune. (This is still true.)
In Pixelmator you get a really cute method for picking the centre of the effect, but the slider for controlling “how much” of the effect is insanely biased to the “too much” end of things (basically about 15% of the way to the right is more than you’d ever need to use) and there’s no way to type in exactly how much you want. Cleverly, Pixelmator generates its preview by using Core Image, but only at screen resolution so it’s more responsive than Acorn. Unfortunately, when you actually apply the effect you get a beach ball because Pixelmator’s UI isn’t designed to handle slower filters gracefully.
In Photoline you get a big ugly dialog box which lets you preview with a small but scrollable and zoomable window with a draggable “before/after splitter”. You can also preview on the whole screen, click where you want the centre of the effect (in the preview pane or the view behind it). And you can set the intensity with a slider or type it in.
So in summary, Acorn has a really elegant UI for stuff you probably don’t need and a lousy one for stuff you do need, almost as if it’s never really been used all that much by anyone except to dick around, Pixelmator has a pretty UI that works well if you’re not editing a high resolution image and/or using filters that don’t benefit much from CoreImage acceleration, and Photoline has a butt-ugly UI that does the job really well and has obviously been thought out and tested.
A More Detailed Comparison
| Category | Pixelmator 1.4 | Acorn 1.52 | Photoline 15.03 |
|---|---|---|---|
| Simple Painting Tools | Basic but servicable | Rudimentary | You name it, it’s there |
| Text | Cocoa text with nice drop shadows | Cocoa text with nice drop shadows | Fully styled and formatted text with both character and paragraph stylesheets and layer effects like emboss and drop shadow |
| Layer Support | Blend Mode and Opacity, Text Layers | Blend Mode and Opacity, Text Layers, Simple Vector Layers | Blend Mode, Opacity, Layer Effects, Filter Layers, Vector Layers, Text Layers, Layers can be different modes (e.g. you can have 16-bit color, 8-bit color, Layer Masks, and monochome layers in a single document) |
| Filters | Excellent Core Image support | Uneven Core Image support (really nice compositing features but marred by lack of weaker (see correction, above) interactivity for things like setting points) | Comprehensive set of filters (including some marked improvements over Photoshop) but no Core Image support. Stuff that Core Image doesn’t give you like comprehensive noise reduction tools, and fractal clouds. Oh and you can create and reuse named presets for almost everything. |
| Vector Layers | None | Rudimentary | Full vector support with strong bezier tools and SVG import/export |
| Non-destructive editing | Not supported | You can composite filters interactively in interesting (non-destructive) ways, but ultimately the operation is destructive | Non-destructive effects layers for most image adjustments (e.g. curves, levels, hue/saturation) |
| Image Format Support | 8-bits per channel RGBA | 8-bits per channel RGBA | 16-bits per channel support, Greyscale, Monochrome, Lab color, CMYK |
| Digital Photography Support | You can import photos in 24-bit color | You can import photos in 24-bit color | Direct RAW import to 24-bit or 48-bit (16 bits per channel) |
| Architecture | Some clever optimizations (e.g. filter previews appear to be at screen resolution) but chokes on large files. | Chokes on large images and slower filters. | Clever and flexible preview system allows you to keep the program responsive when working with huge files, 64-bit support, heterogeneous layer support |
| Workflow and Automation | Some Automator actions (but no AppleScript dictionary) | Python script support | Recordable macros and batch conversion, Save named presets for almost anything, enter expressions for numerical inputs |
| Plugin Support | You can probably build your own using the Quartz Compositor tools from Apple. | You can probably build your own using the Quartz Compositor tools from Apple, and there’s extensive support for creating extensions using Python. | Supports Photoshop plugins. |
| File Format Support | Pixelmator, Photoshop, PNG, GIF, JPEG, JPEG2000, TIFF, BMP, SGI, TGA, PICT, PDF, and a dizzying number of export options | Acorn, PNG, GIF, JPEG, JPEG2000, TIFF, BMP | Pixelmator, Photoshop, PNG, TIFF, JPEG, JPEG2000, BMP, PCX, TGA, Mac Icon, Windows Icon, Windows Cursor, and a bunch more, and can import and export to an even larger number of options, notably including export to SWF and import RAW |
| Cute Stuff | Live gradients, the “dangling rope” that joins position widgets to filter control floaters | Gorgeous Icon, Filter Compositor, Elegant Minimalist UI | Amazing gradient tool, full-featured yet it still launches amazingly fast, 64-bit support |
| Ugly Stuff | Beach ball for slower filters | Filter position controls require you to type in coordinates, (see correction, above) Minimalist Functionality (for a $50 app) and half-assed features (like vector layers with rectangles, ovals, and lines (only). | OMG the icon … it burns! (Sadly, Pixelmator 15 introduced a new icon that’s just as ugly as the old one), half-assed web export and page layout features clutter UI without being useful |
| If I could add one thing from Photoshop | Vector support | Pretty much everything | Layer management functions such as organizing layers into folders (and set folder compositing properties) and being able to use one layer as a mask for layers adjacent to it. |
| Online Community | Active Forum | None | Active Forum |
| Price | $59.00 | $49.95 | €59.00 |
As you can see, Photoline also wins, hands down, on the functionality front, offering much of the functionality of Photoshop* and then some, along with live editable gradients (not quite as “cute” as Pixelmator’s live preview, but more useful), formula support (type arithmetic expressions pretty much anywhere), variable blur (a gaussian blur where radius is controlled by masking — allowing you to simulate depth of field properly), an image browser that doesn’t suck, 64-bit support, and cross-platform licensing (oddly enough, it’s actually more attractive on the Mac than Windows though). And it still launches in less than a second — as do Acorn and Pixelmator.
Summing Up
Pixelmator has come a long way in the year-or-so since it entered with a big splash. Acorn has languished since it  won a bunch of awards and rave reviews, and Photoline has lengthened its considerable lead in robustness and functionality over pretty much everything except the gold standard.
Unfortunately for Photoline it has to compete with Paintshop Pro on Windows, and its lack of Mac-hip-allure on the Mac. Pixelmator is great for people who really aren’t doing anything very challenging — it looks cool and hey, you’re supporting indie Mac-only developers. On the other side of the equation Photoline is good but unglamorous — the question remains whether its few notable deficiencies (e.g. rudimentary layer management) outweigh its technical strongpoints (64-bit support, general snappiness, heterogeneous layer support). There’s no question that for actual professional users, Photoshop is unbeatable (except on 64-bit support — but who really needs that yet?) and well worth the money.
And finally, Acorn has become something of a joke. Its biggest new feature since I last compared these programs has been a new icon. I mean, really.
So… what is Photoline missing?
OK. Photoline sounds pretty great… so why use Photoshop at all? Photoshop has amazingly strong layer management tools (folders — which can have their own compositing settings and can be moved and scaled as one, and the amazingly useful layer-as-mask feature) which are vital to many users (if you’re prototyping UIs with Photoshop and have 500 layers in a document, then Photoline is going to be useless for you).
Photoshop also has pretty strong features for 3D texture painting and compositing (especially as of CS4) which none of these programs even attempt.
Edit: perhaps most important of all, Photoline takes some ugly shortcuts in bezier rendering that will definitely matter to professional designers. If you stroke an arbitrary object in Photoshop, the program infers a border path and then strokes it with a uniform width path. Photoline in essence uses a simple matrix transformation to build the outline leading to the stroke varying in width as it changes angle. Since this algorithm is used in many, many places (e.g. many layer effects), a lot of graphic design work, especially text layout, will look wrong and unprofessonal if executed in Photoline.
And finally, Photoshop has some “rocket science math” features such as the bleeding edge “selective scaling” function (which creates or throws out irrelevant content rather than stretching or squashing everything), panorama stitching (which is very hard to get right), a very good — some consider it the best — RAW importer, supports both scripting and a huge number of plugins — but even here I should note (thanks to an alert reader) that Photoline supports third-party Photoshop plugins and has better built-in noise reduction tools than Photoshop.
If none of this matters to you, then get Photoline and save a ton of money (and probably quite a bit of time). It’s not like Photoshop has that great a UI either. (Edit: and CS4’s UI is remarkably horrible.)
Final Note
You might also find this article on the Top 5 Alternatives to Photoshop helpful. I did.