My First Ever Applescript

A discussion on dpreview.com about Aperture and how it doesn't read maker note EXIF fields, specifically the Lens ID, got me thinking. The wonderful exiftool can read this data, why can't Aperture with its team of crack Apple programmers?

I thought of a workaround. Aperture supports the addition of arbitrary metadata to images, and I use it for things like saving the URL and flickr ID of the photos I upload there. Why not read the data from the image using exiftool and stick the result into a new custom field.

I have diddled around with Applescript in the past, but never really did anything that worked. I got bits & pieces working here and there, but never finished because the need went away, I figured out how to do it some other way (like in Perl), found someone else's solution or some similar result. This task didn't seem too hard, so I poked around and found out that there is Applescript support to write custom metadata.

I then encountered the big hurdle. Talking to Aperture with Applescript is easy and you can do a lot of stuff, but everything is relative to the program's internal database, yet I need the path to the actual image file so that exiftool can do its thing. I didn't see an easy way to get Aperture to reveal a path to the original file or get a reference to the image in Aperture's database based on the path of the image file.

Frustrating! I know both bits of data, I just had no clue how to use them to get to my end result. And I still don't, really, because somebody else figured it out and did the heavy lifting for me: Brett Gross' "Reveal Photo File" Applescript. This handy tool will reveal in the Finder the currently selected image(s) in Aperture. Mr. Gross was kind enough to distribute his Applescript in a readable form, so I was able to yank out the bits that open the finder window and instead squirt the path over to exiftool, get the data I need and then write it back to Aperture.



So now this script is chugging away on my 15k images. It's not the fastest, but most of the slowdown seems to be due to the size of my Aperture library. I tried it on a smaller library of about 200 images and it was done in a minute or two. The current task has been running for a couple days, and at the rate it is going, it will require a couple more. Really strange. And frustrating, because my CPUs are never going above 50% utilization and I have a >1GB of free RAM. I guess the disk is the bottleneck here. I just don't understand why the execution time is so non-linear.

My next step will be to write a new version of the script that will do this all at import, which I hope will be faster.

Please read my post at dpreview.com for the download link and instructions for use.