Re:Apple Create ML: Creating an Image Classifier Model
by Someone on Monday November 30, 2020 @11:47AM
(#25255767)
That project also has code for converting from quite a few formats (https://coremltools.readme.io/docs) to CoreML.
Having that (3-clause BSD-licensed) code will help in writing the reverse converters.
https://apple.github.io/coremltools/coremlspecification/