how to save, restore, make predictions with siames

I am trying to develop a siamese network for simple face verification (and recognition in the second stage). I have a network in place that I managed to train but I am a bit puzzled when it comes to how to save and restore the model + making predictions with the trained model. Hoping that maybe an experienced person in the domain can help to make progress..

Here is how I create my siamese network, to begin with...

model = ResNet50(weights='imagenet')   # get the original ResNet50 model
model.layers.pop()   # Remove the last layer
for layer in model.layers:
    layer.trainable = False   # do not train any of original layers

x = model.get_layer('flatten_1').output
model_out = Dense(128, activation='relu',  name='model_out')(x)
model_out = Lambda(lambda  x: K.l2_normalize(x,axis=-1))(model_out)
new_model = Model(inputs=model.input, outputs=model_out)

# At this point, a new layer (with 128 units) added and normalization applied.

# Now create siamese network on top of this

anchor_in = Input(shape=(224, 224, 3))
positive_in = Input(shape=(224, 224, 3))
negative_in = Input(shape=(224, 224, 3))

anchor_out = new_model(anchor_in)
positive_out = new_model(positive_in)
negative_out = new_model(negative_in)

merged_vector = concatenate([anchor_out, positive_out, negative_out], axis=-1)

# Define the trainable model
siamese_model = Model(inputs=[anchor_in, positive_in, negative_in],
                      outputs=merged_vector)
siamese_model.compile(optimizer=Adam(lr=.0001), 
                      loss=triplet_loss, 
                      metrics=[dist_between_anchor_positive,
                               dist_between_anchor_negative])

And I train the siamese_model. When I train it, if I interpret results right, it is not really training the underlying model, it just trains the new siamese network (essentially, just the last layer is trained).

But this model has 3 input streams. After the training, I need to save this model in a way so that it just takes 1 or 2 inputs so that I can perform predictions by calculating the distance between 2 given images. How do I save this model and reuse it now?

Thank you in advance!

ADDENDUM:

In case you wonder, here is the summary of siamese model.

siamese_model.summary()

__________________________________________________________________________________________________
Layer (type)                    Output Shape         Param #     Connected to                     
==================================================================================================
input_2 (InputLayer)            (None, 224, 224, 3)  0                                            
__________________________________________________________________________________________________
input_3 (InputLayer)            (None, 224, 224, 3)  0                                            
__________________________________________________________________________________________________
input_4 (InputLayer)            (None, 224, 224, 3)  0                                            
__________________________________________________________________________________________________
model_1 (Model)                 (None, 128)          23849984    input_2[0][0]                    
                                                                 input_3[0][0]                    
                                                                 input_4[0][0]                    
__________________________________________________________________________________________________
concatenate_1 (Concatenate)     (None, 384)          0           model_1[1][0]                    
                                                                 model_1[2][0]                    
                                                                 model_1[3][0]                    
==================================================================================================
Total params: 23,849,984
Trainable params: 262,272
Non-trainable params: 23,587,712
__________________________________________________________________________________________________

You can use below code to save your model siamese_model.save_weights(MODEL_WEIGHTS_FILE)

And then to load your model you need to use siamese_model.load_weights(MODEL_WEIGHTS_FILE)

Thanks