I'm no longer maintaining this repo, but @bit-man has a slightly more up-to-date fork at https://github.com/bit-man/shotwell-iphoto-import

This repository contains a script to import an iPhoto library into Shotwell.

It preserves modified images using Shotwell's "open in external editor" feature. Images that you tweaked in iPhoto will appear to have been modified in an external editor in Shotwell. i.e. it will show the tweaked version by default and allow you to do non-destructive editing to the tweaked version or revert to the original and lose your iPhoto tweaks.

To use the script you will need to pass it

• the path of your shotwell database; the default is '~/.local/share/shotwell/data/photo.db'
• the path of the iPhoto Library directory
• a destination path to copy photos to. E.g. "~/Pictures/"

The script will copy the photos using the directory hierarchy of the iPhoto Library but within your selected pictures folder. Note: the script will try to use a hard link rather than a copy if possible. They means that the two paths will actually point at the same file. This saves disk space but if you subsequently modify the file under iPhoto Library, it will affect the Shotwell copy too.

./iphoto_import.py --shotwell-db '/.local/share/shotwell/data/photo.db' '/iPhoto\ Library/' ~/Pictures/

• Movies are not imported, but they are copied to the destination.
• The script checks the version of the Shotwell and iPhoto libraries to make sure they are compatible. If will reject versions it doesn't understand.
• It's a bit slow. 10+ minutes to import 17k photos.
• Shotwell will spin for a long time after the import while it generates thumbnails. This took over an hour for my 17k photos.