Acorn is my favorite image editor for OS X (I liked the changes in version 4.0) because it’s powerful but easy to use. The way that Acorn organizes filters and layers and lets you interact with them in the tools palette just makes sense for the way I want my image editor to work. Version 4.2, released last week for website customers, brings some welcome additions – I’m especially a fan of the Share menu and tweaks to selections.

The technical changes are also worth noting:

Pixels get to the screen so much faster now that everything is drawn through OpenGL.  Not only that, but Acorn takes advantage of OpenCL by virtue of using Core Image. Acorn also uses custom OpenCL kernels I hand coded to speed up other operations.  Acorn incorporates some super fast algorithms combined with GCD to minimize the amount of drawing that happens. Less drawing means longer battery life and overall things go faster.

I had mentioned in a previous post that I was reworking the compositing engine.  I’m not done with that yet, but the progress I have made is promising.  So with a bit more work and time, things are going to get even faster for Acorn.