tf.GraphKeys.TRAINABLE_VARIABLES on output_graph.pb resulting in empty list

Question

I\'m trying to extract all the weights/biases from a saved model output_graph.pb.

I read the model:

def create_graph(modelFullPath):
    \"\         


        

Answer 1

The tf.import_graph_def() function doesn't have enough information to reconstruct the tf.GraphKeys.TRAINABLE_VARIABLES collection (for that, you would need a MetaGraphDef). However, if output.pb contains a "frozen" GraphDef, then all of the weights will be stored in tf.constant() nodes in the graph. To extract them, you can do something like the following:

create_graph(GRAPH_DIR)

constant_values = {}

with tf.Session() as sess:
  constant_ops = [op for op in sess.graph.get_operations() if op.type == "Const"]
  for constant_op in constant_ops:
    constant_values[constant_op.name] = sess.run(constant_op.outputs[0])

Note that constant_values will probably contain more values than just the weights, so you may need to filter further by op.name or some other criterion.