Key ssd_300_vgg/block3_box/L2Normalization/gamma not found in checkpoint的解决方案

在Tensorflow下使用SSD模型训练自己的数据集时，经过查找很多博客资料，已经成功训练出来了自己的模型，但就是在测试自己模型效果的时候，出现了如下错误。

2019-10-27 14:47:12.862573: W tensorflow/core/framework/op_kernel.cc:1401] OP_REQUIRES failed at save_restore_v2_ops.cc:184 : Not found: Key ssd_300_vgg/block3_box/L2Normalization/gamma not found in checkpoint
Traceback (most recent call last):
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/client/session.py", line 1334, in _do_call
    return fn(*args)
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/client/session.py", line 1319, in _run_fn
    options, feed_dict, fetch_list, target_list, run_metadata)
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/client/session.py", line 1407, in _call_tf_sessionrun
    run_metadata)
tensorflow.python.framework.errors_impl.NotFoundError: Key ssd_300_vgg/block3_box/L2Normalization/gamma not found in checkpoint
         [[{{node save/RestoreV2}}]]
         [[{{node save/RestoreV2}}]]

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/training/saver.py", line 1276, in restore
    {self.saver_def.filename_tensor_name: save_path})
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/client/session.py", line 929, in run
    run_metadata_ptr)
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/client/session.py", line 1152, in _run
    feed_dict_tensor, options, run_metadata)
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/client/session.py", line 1328, in _do_run
    run_metadata)
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/client/session.py", line 1348, in _do_call
    raise type(e)(node_def, op, message)
tensorflow.python.framework.errors_impl.NotFoundError: Key ssd_300_vgg/block3_box/L2Normalization/gamma not found in checkpoint
         [[node save/RestoreV2 (defined at ssd_notebook.py:53) ]]
         [[node save/RestoreV2 (defined at ssd_notebook.py:53) ]]

Caused by op 'save/RestoreV2', defined at:
  File "ssd_notebook.py", line 53, in <module>
    saver = tf.train.Saver()
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/training/saver.py", line 832, in __init__
    self.build()
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/training/saver.py", line 844, in build
    self._build(self._filename, build_save=True, build_restore=True)
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/training/saver.py", line 881, in _build
    build_save=build_save, build_restore=build_restore)
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/training/saver.py", line 513, in _build_internal
    restore_sequentially, reshape)
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/training/saver.py", line 332, in _AddRestoreOps
    restore_sequentially)
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/training/saver.py", line 580, in bulk_restore
    return io_ops.restore_v2(filename_tensor, names, slices, dtypes)
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/ops/gen_io_ops.py", line 1572, in restore_v2
    name=name)
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/framework/op_def_library.py", line 788, in _apply_op_helper
    op_def=op_def)
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/util/deprecation.py", line 507, in new_func
    return func(*args, **kwargs)
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/framework/ops.py", line 3300, in create_op
    op_def=op_def)
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/framework/ops.py", line 1801, in __init__
    self._traceback = tf_stack.extract_stack()

NotFoundError (see above for traceback): Key ssd_300_vgg/block3_box/L2Normalization/gamma not found in checkpoint
         [[node save/RestoreV2 (defined at ssd_notebook.py:53) ]]
         [[node save/RestoreV2 (defined at ssd_notebook.py:53) ]]

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/training/saver.py", line 1286, in restore
    names_to_keys = object_graph_key_mapping(save_path)
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/training/saver.py", line 1591, in object_graph_key_mapping
    checkpointable.OBJECT_GRAPH_PROTO_KEY)
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/pywrap_tensorflow_internal.py", line 370, in get_tensor
    status)
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/framework/errors_impl.py", line 528, in __exit__
    c_api.TF_GetCode(self.status.status))
tensorflow.python.framework.errors_impl.NotFoundError: Key _CHECKPOINTABLE_OBJECT_GRAPH not found in checkpoint

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "ssd_notebook.py", line 54, in <module>
    saver.restore(isess, ckpt_filename)
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/training/saver.py", line 1292, in restore
    err, "a Variable name or other graph key that is missing")
tensorflow.python.framework.errors_impl.NotFoundError: Restoring from checkpoint failed. This is most likely due to a Variable nameor other graph key that is missing from the checkpoint. Please ensure that you have not altered the graph expected based on the checkpoint. Original error:

Key ssd_300_vgg/block3_box/L2Normalization/gamma not found in checkpoint
         [[node save/RestoreV2 (defined at ssd_notebook.py:53) ]]
         [[node save/RestoreV2 (defined at ssd_notebook.py:53) ]]

Caused by op 'save/RestoreV2', defined at:
  File "ssd_notebook.py", line 53, in <module>
    saver = tf.train.Saver()
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/training/saver.py", line 832, in __init__
    self.build()
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/training/saver.py", line 844, in build
    self._build(self._filename, build_save=True, build_restore=True)
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/training/saver.py", line 881, in _build
    build_save=build_save, build_restore=build_restore)
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/training/saver.py", line 513, in _build_internal
    restore_sequentially, reshape)
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/training/saver.py", line 332, in _AddRestoreOps
    restore_sequentially)
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/training/saver.py", line 580, in bulk_restore
    return io_ops.restore_v2(filename_tensor, names, slices, dtypes)
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/ops/gen_io_ops.py", line 1572, in restore_v2
    name=name)
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/framework/op_def_library.py", line 788, in _apply_op_helper
    op_def=op_def)
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/util/deprecation.py", line 507, in new_func
    return func(*args, **kwargs)
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/framework/ops.py", line 3300, in create_op
    op_def=op_def)
  File "/opt/anaconda3/envs/dlipy3/lib/python3.6/site-packages/tensorflow/python/framework/ops.py", line 1801, in __init__
    self._traceback = tf_stack.extract_stack()

NotFoundError (see above for traceback): Restoring from checkpoint failed. This is most likely due to a Variable name or other graph key that is missing from the checkpoint. Please ensure that you have not altered the graph expected based on the checkpoint. Original error:

Key ssd_300_vgg/block3_box/L2Normalization/gamma not found in checkpoint
         [[node save/RestoreV2 (defined at ssd_notebook.py:53) ]]
         [[node save/RestoreV2 (defined at ssd_notebook.py:53) ]]

在查找资料的过程中，出现了很多波折，百度上基本没有同样的错误，

最开始使用的代码是：

ckpt_filename = '../train_model/model.ckpt-1000'

尝试过很多种方法，比如下面这种方法，改了后还是报同样的错误。

ckpt_filename =  tf.train.latest_checkpoint('../train_model/model.ckpt-1000')

还有说模型没有完全保存，经过很多次训练，发现模型确实是成功保存了的。

还说是按照这个英文意思来解决，就是这个Key在ckpt文件里面没有。经查找资料用如下代码查看ckpt文件里面的key。

import os
from tensorflow.python import pywrap_tensorflow

current_path = '****/SSD_small_object_detection/'
model_dir = os.path.join(current_path, 'train_model')
checkpoint_path = os.path.join(model_dir,'model.ckpt-1000') # 保存的ckpt文件名，不一定是这个
# Read data from checkpoint file
reader = pywrap_tensorflow.NewCheckpointReader(checkpoint_path)
var_to_shape_map = reader.get_variable_to_shape_map()
# Print tensor name and values
for key in var_to_shape_map:
    print("tensor_name: ", key)
    # print(reader.get_tensor(key)) # 打印变量的值，对我们查找问题没啥影响，打印出来反而影响找问题

确实得到了一点结果，如下图所示：

　　

就算得到了结果，但是代码太复杂，本身也看不太懂，就想着实在没办法的话就尝试Debug下代码，但是我相信前面的步骤没有问题，然后终于发现了解决方法。

　　

于是我在我自己的代码中将saver的定义改变一下

saver = tf.train.import_meta_graph("../train_model/model.ckpt-1000.meta")

错误成功解决。