python - ValueError: Unknown layer: CapsuleLayer

Question

I have defined a custom layer named CapsuleLayer. The actual model has been defined in a separate class. I have loaded the weights into the actual model and have saved the model in an .h5 file. However when I try to load the model using load_model(filepath) I get the error

ValueError: Unknown layer: CapsuleLayer

How can I incorporate the custom layer into my model while loading the saved model.

Answer 1

C.f. Keras FAQ, "Handling custom layers (or other custom objects) in saved models":

If the model you want to load includes custom layers or other custom classes or functions, you can pass them to the loading mechanism via the custom_objects argument:

from keras.models import load_model
# Assuming your model includes instance of an "AttentionLayer" class
model = load_model('my_model.h5', custom_objects={'AttentionLayer': AttentionLayer})

Alternatively, you can use a custom object scope:

from keras.utils import CustomObjectScope

with CustomObjectScope({'AttentionLayer': AttentionLayer}):
    model = load_model('my_model.h5')

Custom objects handling works the same way for load_model, model_from_json, model_from_yaml:

from keras.models import model_from_json
model = model_from_json(json_string, custom_objects={'AttentionLayer': AttentionLayer})

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In your case, model = load_model('my_model.h5', custom_objects={'CapsuleLayer': CapsuleLayer}) should solve your problem.