14 DAY TRIAL // There are a lot of image editors out there; however, most of the shareware and freeware ones are simplistic and pale when compared to the higher end, professional image editing applications.
While without a doubt there should be clear differences between shareware programs and professional applications, these differences are usually very significant, and more often than not, if you need a few extra features than your average shareware software can offer, you have to go all the distance and buy a professional app because you can't find anything in between. Apple does not offer a default image editing application, however, the CoreImage technology that is present in OS X contains many powerful functions that anyone can harness, and such is the story of LiveQuartz.
What it does
LiveQuartz is an image editor that is somewhere in the middle grounds, between shareware applications and professional image editing apps. It makes use of CoreImage to give you access to many effects and filters that you can mix and stack using layers.
LiveQuartz uses the built in capabilities of the system to give you a lot more than just the average run of the mill program.
Tools
All of the tools present in the program are pretty basic, but they are very well implemented, with approaches that are sometimes intuitive, and sometimes annoying.
The brush and eraser tool work as expected, but there are small things about them. For example, using the eraser tool on a layer will erase from it, but it will look like you are drawing with a black brush, unlike traditional applications where what was there simply disappeared. This gets even more confusing when you are erasing parts of a black image. You are painting with black on black, in order to erase? you might just as well be working in the dark with your eyes closed.
On the other hand, when you are working on a certain layer, the program will hide all other layers so you can better see what you are doing. Then again, if that layer also had a filter applied to it, the filter will not be shown, meaning that you cannot see the changes until they are made.
The selection tools, on the other hand work similar to the way they do in professional applications, in that you can make a selection and then paint, only within that selection. Unfortunately, unlike the professional apps, there is not much in the way of making custom selections, and you basically have to choose between a rectangle and lasso tool.
Layers
Fortunately, LiveQuartz has a pretty good layer implementation that lets you make use of drag and drop and other options to make complex compositions more manageable. The only things it cannot do is make folders for easer management of large numbers of layers, and layer linking.
While the layers are not as powerful as they could be, they are nevertheless useful and you can easily make the most out of them? after all, any layer implementation is better than no layer implementation.
Filters and effects
Like Photoshop, LiveQuartz lets you apply effects and filters to images. These effects and filters can be stacked and layered, and they are flexible as you can change the settings of any filter at any given time. This makes it better in a way than other implementation, where the only way to change a filter once applied is to undo it.
There are plenty of choices in the list, ranging from blurs and distortions to color tweaks and other stylizations. All of these can be changed, tweaked and reordered; however, the interface is key to getting the most out of them.
Because of the way that the filters work, and can be edited at any time, all the changes you make can sometimes take a long time to render, making it a pain to work with. While sliders and controls are all good and fine when you have constant visual feedback, with this program that is not always the case. As such, manual input of values is preferable, but this is not readily apparent unless you change the interface to 'drawers mode.' Even in the default layout, you can have a third additional drawer open at the bottom of the screen by clicking the little button with three dots at the bottom of the filters view. Not only will this allow you to manually enter values, but it will also let you use a much larger slider giving you more precision.
The Good
More capable than most other non professional image editing applications, with decent tools, layers and filters.
The Bad
Tries to do some things differently, which results in some absurd situations such as painting with black on black in order to erase parts of an image.
The Truth
If you want more than the average image editing app, but are not quite up for a full blown professional application, LiveQuartz might be just the right program for you.
Here are some screenshots, click to enlarge:
