I recently spent two weeks converting JustLooking, my Mac OS X Image Viewing program, from NSImage to CoreImage and friends. This experience was overall much easier than I expected, and I have learned a bunch of things, some of which might have been handy to have known in advance.

The good news is that it mostly lives up to the hype. The bad news is that it’s not without tricks and traps of its own. Here are some notes and comments.