Yes, you have hit on a big problem I have yet to address with Project Threepio. ImageMagick works great for ALMOST all image operations, but the whole ImageMagick+Pango text rendering business is very, very fragile and limited. The last version to work on Windows was 7.0.10-23, and Linux may be similarly version-limited (I didn’t discover this until after the current version was released, so it’s not in the README). The latest and greatest ImageMagick seems broken, and ImageMagick doesn’t archive old versions anywhere. Even with the correct Windows version, some scripts won’t render properly on that platform and must be done on Linux.
I am actually in the process of re-writing the text renderer right now, using something other than ImageMagick+Pango to turn the text into images (Google Chrome, actually). However, this is far from done and unlikely to even make it into the next version, so we’re looking two versions out for a complete fix. The goal is complete cross-platform support, greater certainty of long-term future support, and no loss in functionality. You’ll notice I didn’t say performance. The new version of the script appears to be even slower, and for those who have run the current one, you’ll know that’s really saying something.
So all I can suggest right now is to try older ImageMagick versions, or use the specific version I mentioned on Windows. For now, that’s all I can suggest. I just chose the wrong technical foundation for text rendering, mea culpa.
I’ve found this place that hosts old ImageMagick binaries (if you’re the sort to trust random binaries from the Internet):
https://ftp.icm.edu.pl/packages/ImageMagick/binaries/?C=N;O=D
The good news is that regardless of all of this, there WILL be a solution for the mono mix (for both Star Wars and Empire, and the 1981/1985/1993 versions too) in the next version of Project Threepio. It’s not “there” yet, but I can say it’s pretty close. Maybe within the next couple months, I’m just waiting for some new translations to come in. So if you can wait for this, there will be something for you that’ll be much faster and easier then.
EDIT: You dove into the Python code of the text renderer script?!? You’re braver than I thought!