So as Steve Troughton-Smith revealed, Apple’s AirPrint functionality had three components: two config files and a CUPS image filter. The config files are simple enough to replicate, but the filter was more involved. It needed to be able to take UNIRAST images (identified by the image/urf MIME type) and output pdf data. The problem, naturally, was that UNIRAST isn’t a well-documented format. However, there were enough clues that it was possible to figure out what was going on.
As a result, I now have the majority of the work done for enabling AirPrint in the same manner as Apple’s original implementation on OS X 10.6.5. The source for my version of the urf-to-pdf CUPS filter is now available on github and I’ll be putting together an installer package later today to do the whole job for you.
