Plugin broken by latest Lektor

[dairiki]

The Lektor PRs lektor/lektor#1104 (already merged to master) switches from using ImageMagick to using Pillow for thumbnail generation. (PR lektor/lektor#1138 is continuing work on that new code.) At this point, the new code is only in the pre-release branch. Install Lektor>=3.4.0b6 to try it out.

I'm fairly certain that has broken this plugin. Is that a problem? If so, let's figure out how to fix it.

Since Lektor no longer uses ImageMagick, if you want to continue to do so here, you're on your own.
But if it doesn't involve too much hackage, Lektor could probably provide a general-purpose API for resizing images that would work (i.e. a replacement for process_image) for this plugin. (Or, you could just use Pillow directly.) If you're interested in something from Lektor's side, let me know.