我正在尝试在 Keras 中使用内置模型。
这很有效：
import tensorflow as tf
keras = tf.contrib.keras
imgs = tf.placeholder(tf.float32, shape=(None, 150, 150, 3))
x = keras.applications.InceptionV3(weights='imagenet', include_top=False, pooling='avg', input_shape=(150,150,3))(imgs)
这不是：
import tensorflow as tf
keras = tf.contrib.keras
init_imgs = tf.placeholder(dtype=tf.float32)
imgs = tf.get_variable('imgs', initializer=init_imgs, trainable=False, validate_shape=False, dtype=tf.float32)
x = keras.applications.InceptionV3(weights='imagenet', include_top=False, pooling='avg', input_shape=(150,150,3))(imgs)
它You must feed a value for placeholder tensor 'Placeholder' with dtype float出错，但我没有 sess.run((。为什么当我只是尝试构建图形时它会抱怨饲料？
加
这是堆栈跟踪。错误来自model.load_weights.但是，我认为加载 InceptionV3 权重应该独立于图形的其他部分。
---------------------------------------------------------------------------
InvalidArgumentError Traceback (most recent call last)
/usr/local/lib/python3.5/dist-packages/tensorflow/python/client/session.py in _do_call(self, fn, *args)
1138 try:
-> 1139 return fn(*args)
1140 except errors.OpError as e:
/usr/local/lib/python3.5/dist-packages/tensorflow/python/client/session.py in _run_fn(session, feed_dict, fetch_list, target_list, options, run_metadata)
1120 feed_dict, fetch_list, target_list,
-> 1121 status, run_metadata)
1122
/usr/lib/python3.5/contextlib.py in __exit__(self, type, value, traceback)
65 try:
---> 66 next(self.gen)
67 except StopIteration:
/usr/local/lib/python3.5/dist-packages/tensorflow/python/framework/errors_impl.py in raise_exception_on_not_ok_status()
465 compat.as_text(pywrap_tensorflow.TF_Message(status)),
--> 466 pywrap_tensorflow.TF_GetCode(status))
467 finally:
InvalidArgumentError: You must feed a value for placeholder tensor 'my_own_placeholder' with dtype float
[[Node: my_own_placeholder = Placeholder[dtype=DT_FLOAT, shape=<unknown>, _device="/job:localhost/replica:0/task:0/gpu:0"]()]]
During handling of the above exception, another exception occurred:
InvalidArgumentError Traceback (most recent call last)
<ipython-input-1-cf7678dd8501> in <module>()
8 imgs = tf.get_variable('imgs', initializer=init_imgs, trainable=False, validate_shape=False, dtype=tf.float32)
9
---> 10 x = keras.applications.InceptionV3(weights='imagenet', include_top=False, pooling='avg', input_shape=(150,150,3))(imgs)
/usr/local/lib/python3.5/dist-packages/tensorflow/contrib/keras/python/keras/applications/inception_v3.py in InceptionV3(include_top, weights, input_tensor, input_shape, pooling, classes)
394 cache_subdir='models',
395 md5_hash='bcbd6486424b2319ff4ef7d526e38f63')
--> 396 model.load_weights(weights_path)
397 if K.backend() == 'theano':
398 convert_all_kernels_in_model(model)
/usr/local/lib/python3.5/dist-packages/tensorflow/contrib/keras/python/keras/engine/topology.py in load_weights(self, filepath, by_name)
2279 load_weights_from_hdf5_group_by_name(f, self.layers)
2280 else:
-> 2281 load_weights_from_hdf5_group(f, self.layers)
2282
2283 if hasattr(f, 'close'):
/usr/local/lib/python3.5/dist-packages/tensorflow/contrib/keras/python/keras/engine/topology.py in load_weights_from_hdf5_group(f, layers)
2666 str(len(weight_values)) + ' elements.')
2667 weight_value_tuples += zip(symbolic_weights, weight_values)
-> 2668 K.batch_set_value(weight_value_tuples)
2669
2670
/usr/local/lib/python3.5/dist-packages/tensorflow/contrib/keras/python/keras/backend.py in batch_set_value(tuples)
2222 assign_ops.append(assign_op)
2223 feed_dict[assign_placeholder] = value
-> 2224 get_session().run(assign_ops, feed_dict=feed_dict)
2225
2226
/usr/local/lib/python3.5/dist-packages/tensorflow/contrib/keras/python/keras/backend.py in get_session()
369 if not _MANUAL_VAR_INIT:
370 with session.graph.as_default():
--> 371 _initialize_variables()
372 return session
373
/usr/local/lib/python3.5/dist-packages/tensorflow/contrib/keras/python/keras/backend.py in _initialize_variables()
518 if uninitialized_variables:
519 sess = get_session()
--> 520 sess.run(variables_module.variables_initializer(uninitialized_variables))
521
522
/usr/local/lib/python3.5/dist-packages/tensorflow/python/client/session.py in run(self, fetches, feed_dict, options, run_metadata)
787 try:
788 result = self._run(None, fetches, feed_dict, options_ptr,
--> 789 run_metadata_ptr)
790 if run_metadata:
791 proto_data = tf_session.TF_GetBuffer(run_metadata_ptr)
/usr/local/lib/python3.5/dist-packages/tensorflow/python/client/session.py in _run(self, handle, fetches, feed_dict, options, run_metadata)
995 if final_fetches or final_targets:
996 results = self._do_run(handle, final_targets, final_fetches,
--> 997 feed_dict_string, options, run_metadata)
998 else:
999 results = []
/usr/local/lib/python3.5/dist-packages/tensorflow/python/client/session.py in _do_run(self, handle, target_list, fetch_list, feed_dict, options, run_metadata)
1130 if handle is None:
1131 return self._do_call(_run_fn, self._session, feed_dict, fetch_list,
-> 1132 target_list, options, run_metadata)
1133 else:
1134 return self._do_call(_prun_fn, self._session, handle, feed_dict,
/usr/local/lib/python3.5/dist-packages/tensorflow/python/client/session.py in _do_call(self, fn, *args)
1150 except KeyError:
1151 pass
-> 1152 raise type(e)(node_def, op, message)
1153
1154 def _extend_graph(self):
InvalidArgumentError: You must feed a value for placeholder tensor 'my_own_placeholder' with dtype float
[[Node: my_own_placeholder = Placeholder[dtype=DT_FLOAT, shape=<unknown>, _device="/job:localhost/replica:0/task:0/gpu:0"]()]]
Caused by op 'my_own_placeholder', defined at:
File "/usr/lib/python3.5/runpy.py", line 184, in _run_module_as_main
"__main__", mod_spec)
File "/usr/lib/python3.5/runpy.py", line 85, in _run_code
exec(code, run_globals)
File "/usr/local/lib/python3.5/dist-packages/ipykernel_launcher.py", line 16, in <module>
app.launch_new_instance()
File "/usr/local/lib/python3.5/dist-packages/traitlets/config/application.py", line 658, in launch_instance
app.start()
File "/usr/local/lib/python3.5/dist-packages/ipykernel/kernelapp.py", line 477, in start
ioloop.IOLoop.instance().start()
File "/usr/local/lib/python3.5/dist-packages/zmq/eventloop/ioloop.py", line 177, in start
super(ZMQIOLoop, self).start()
File "/usr/local/lib/python3.5/dist-packages/tornado/ioloop.py", line 888, in start
handler_func(fd_obj, events)
File "/usr/local/lib/python3.5/dist-packages/tornado/stack_context.py", line 277, in null_wrapper
return fn(*args, **kwargs)
File "/usr/local/lib/python3.5/dist-packages/zmq/eventloop/zmqstream.py", line 440, in _handle_events
self._handle_recv()
File "/usr/local/lib/python3.5/dist-packages/zmq/eventloop/zmqstream.py", line 472, in _handle_recv
self._run_callback(callback, msg)
File "/usr/local/lib/python3.5/dist-packages/zmq/eventloop/zmqstream.py", line 414, in _run_callback
callback(*args, **kwargs)
File "/usr/local/lib/python3.5/dist-packages/tornado/stack_context.py", line 277, in null_wrapper
return fn(*args, **kwargs)
File "/usr/local/lib/python3.5/dist-packages/ipykernel/kernelbase.py", line 283, in dispatcher
return self.dispatch_shell(stream, msg)
File "/usr/local/lib/python3.5/dist-packages/ipykernel/kernelbase.py", line 235, in dispatch_shell
handler(stream, idents, msg)
File "/usr/local/lib/python3.5/dist-packages/ipykernel/kernelbase.py", line 399, in execute_request
user_expressions, allow_stdin)
File "/usr/local/lib/python3.5/dist-packages/ipykernel/ipkernel.py", line 196, in do_execute
res = shell.run_cell(code, store_history=store_history, silent=silent)
File "/usr/local/lib/python3.5/dist-packages/ipykernel/zmqshell.py", line 533, in run_cell
return super(ZMQInteractiveShell, self).run_cell(*args, **kwargs)
File "/usr/local/lib/python3.5/dist-packages/IPython/core/interactiveshell.py", line 2698, in run_cell
interactivity=interactivity, compiler=compiler, result=result)
File "/usr/local/lib/python3.5/dist-packages/IPython/core/interactiveshell.py", line 2802, in run_ast_nodes
if self.run_code(code, result):
File "/usr/local/lib/python3.5/dist-packages/IPython/core/interactiveshell.py", line 2862, in run_code
exec(code_obj, self.user_global_ns, self.user_ns)
File "<ipython-input-1-cf7678dd8501>", line 7, in <module>
init_imgs = tf.placeholder(dtype=tf.float32, name='my_own_placeholder')
File "/usr/local/lib/python3.5/dist-packages/tensorflow/python/ops/array_ops.py", line 1530, in placeholder
return gen_array_ops._placeholder(dtype=dtype, shape=shape, name=name)
File "/usr/local/lib/python3.5/dist-packages/tensorflow/python/ops/gen_array_ops.py", line 1954, in _placeholder
name=name)
File "/usr/local/lib/python3.5/dist-packages/tensorflow/python/framework/op_def_library.py", line 767, in apply_op
op_def=op_def)
File "/usr/local/lib/python3.5/dist-packages/tensorflow/python/framework/ops.py", line 2506, in create_op
original_op=self._default_original_op, op_def=op_def)
File "/usr/local/lib/python3.5/dist-packages/tensorflow/python/framework/ops.py", line 1269, in __init__
self._traceback = _extract_stack()
InvalidArgumentError (see above for traceback): You must feed a value for placeholder tensor 'my_own_placeholder' with dtype float
[[Node: my_own_placeholder = Placeholder[dtype=DT_FLOAT, shape=<unknown>, _device="/job:localhost/replica:0/task:0/gpu:0"]()]]
查看代码，InceptionV3 不仅尝试初始化其权重，还尝试初始化所有 tf.global_variables((。
https://github.com/tensorflow/tensorflow/blob/master/tensorflow/contrib/keras/python/keras/backend.py#L534
因此，当前的 Keras 模型不能用作 Tensorflow 的子图。