I'm trying to do the same, following the WWDC video, but I'm receiving an error:
Error: value type not convertible:
<PIL.JpegImagePlugin.JpegImageFile image mode=RGB size=200x200 at 0x121AC04D0>
---------------------------------------------------------------------------
RuntimeError Traceback (most recent call last)
<ipython-input-38-82fd85392a7f> in <module>()
----> 1 model.predict({'stampImage': image})
/anaconda/envs/coremltools_py2/lib/python2.7/site-packages/coremltools/models/model.pyc in predict(self, data, **kwargs)
236 """
237 if self.__proxy__:
--> 238 return self.__proxy__.predict(data)
239 else:
240 if _sys.platform != 'darwin' or float('.'.join(_platform.mac_ver()[0].split('.')[:2])) < 10.13:
RuntimeError: value type not convertible
The Keras model works fine... Do you have any idea about what is going wrong?