How do I plot a Keras/Tensorflow subclassing API model?

I’ve found some workaround to plot with the model sub-classing API. For the obvious reason Sub-Classing API doesn’t support Sequential or Functional API like model.summary() and nice visualization using plot_model. Here, I will demonstrate both.

class my_model(keras.Model):
    def __init__(self, dim):
        super(my_model, self).__init__()
        self.Base  = keras.keras.applications.VGG16(
            input_shape=(dim), 
            include_top = False, 
            weights="imagenet"
        )
        self.GAP   = L.GlobalAveragePooling2D()
        self.BAT   = L.BatchNormalization()
        self.DROP  = L.Dropout(rate=0.1)
        self.DENS  = L.Dense(256, activation='relu', name="dense_A")
        self.OUT   = L.Dense(1, activation='sigmoid')
    
    def call(self, inputs):
        x  = self.Base(inputs)
        g  = self.GAP(x)
        b  = self.BAT(g)
        d  = self.DROP(b)
        d  = self.DENS(d)
        return self.OUT(d)
    
    # AFAIK: The most convenient method to print model.summary() 
    # similar to the sequential or functional API like.
    def build_graph(self):
        x = Input(shape=(dim))
        return Model(inputs=[x], outputs=self.call(x))

dim = (124,124,3)
model = my_model((dim))
model.build((None, *dim))
model.build_graph().summary()

It will produce as follows:

Layer (type)                 Output Shape              Param #   
=================================================================
input_67 (InputLayer)        [(None, 124, 124, 3)]     0         
_________________________________________________________________
vgg16 (Functional)           (None, 3, 3, 512)         14714688  
_________________________________________________________________
global_average_pooling2d_32  (None, 512)               0         
_________________________________________________________________
batch_normalization_7 (Batch (None, 512)               2048      
_________________________________________________________________
dropout_5 (Dropout)          (None, 512)               0         
_________________________________________________________________
dense_A (Dense)              (None, 256)               402192    
_________________________________________________________________
dense_7 (Dense)              (None, 1)                 785       
=================================================================
Total params: 14,848,321
Trainable params: 14,847,297
Non-trainable params: 1,024

Now by using the build_graph function, we can simply plot the whole architecture.

# Just showing all possible argument for newcomer.  
tf.keras.utils.plot_model(
    model.build_graph(),                      # here is the trick (for now)
    to_file="model.png", dpi=96,              # saving  
    show_shapes=True, show_layer_names=True,  # show shapes and layer name
    expand_nested=False                       # will show nested block
)

It will produce as follows: -)

a


Similar QnA:

  1. Retrieving Keras Layer Properties from a tf.keras.Model
  2. Visualize nested keras.Model (SubClassed API) GAN model

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