iMaginator1.1 review

iMaginator, from long-time NeXTSTEP and Cocoa developer Stone Design, has the rather splendid distinction of being the first image-editing application to be based on Apple's Core Image graphics library.

This library has more than 100 effects that ship with Mac OS X 10.4 (Tiger) and uses the power of the graphics card's graphics processing unit (GPU) to do all the effects calculation, relieving the main CPU from this task. This means you need Tiger and a Core Image-capable graphics card to take advantage of it, but the upside is you get loads of cool effects that you can apply almost instantly to your images. Current graphics cards that support Core Image are ATi Radeons above the 9600 and Nvidia GeForce cards above the 5200 FX, so this rules out the current iBooks and Mac minis. Without a suitable GPU, iMaginator will run using the CPU, albeit much more slowly.

iMaginator presents a tidy, single-window interface, which opens a default image. You can either set this in Preferences or open your own from the File menu. On the left are three panes that contain the guts of the tool set: the Effects List, Effects Chain and the Effects Controls. There are currently 107 effects, and this list will grow as Apple and other developers write Core Image Units. Finding the effect you want from an ever-expanding list can be a chore, but iMaginator is Spotlight-aware, so you can zero in on the effect you want by typing a few letters.

Effects Controls displays a scrollable stack of panes for each Image Unit and lets you set the parameters for each effect - for example, Blur Radius, Colour Correction and Text Size. Effects also display crosshair 'handles' on screen that allow for positioning and some fine tuning. Each Effect pane also allows you to turn each effect on and off.

iMaginator is a non-linear, non-destructive effects processor. To this end, files are saved as the original, unaltered image with their effects chain. Each time the image is opened, the last effects chain is re-applied to the image. Of course, images can also be saved as Tiffs and Jpegs.

The most interesting feature of the lot is the Effects Chain. This shows a small thumbnail with an example of the effect applied, but it also allows you to re-order the sequence of effects by dragging effects around. Effects chains can also be saved, and re-applied to any image by dragging and dropping. In fact, Stone Design is running an effects chain competition on its website, and the entries can be downloaded for you to try.

We used iMaginator on a dual 2GHz G5 with an ATI 9650 graphics card with 256MB of RAM. The speed of applying effects is quite startling. Only when images got to around 2600 x 2000 pixels did things starts to slow down a little. We also noticed some of the effects (such as Vortex) don't scale well to larger images.

Version 1.1 has introduced an option to display only the handles of the currently selected effect: with a large stack of effects, things could get a bit cluttered. However, with all handles displayed, parameters of all the applied effects can be tweaked directly in the editing window without having to go back to the Effects Controls pane.

Many effects are transitions and so have a time slider. These time-dependent effects can then be previewed as a QuickTime movie simply by pressing the Q button in the toolbar and then saving it as a .mov file. Even parameters such as changing the refractive index of the Glass Lozenge effect or the count parameter for the amazing Kaleidoscope effect can be animated.