I have downloaded a tensorflow GraphDef that implements a VGG16 ConvNet, which I use doing this :
Pl['images'] = tf.placeholder(tf.float32,
[None, 448, 448, 3],
name="images") #batch x width x height x channels
with open("tensorflow-vgg16/vgg16.tfmodel", mode='rb') as f:
fileContent = f.read()
graph_def = tf.GraphDef()
graph_def.ParseFromString(fileContent)
tf.import_graph_def(graph_def, input_map={"images": Pl['images']})
Besides, I have image features that are homogeneous to the output of the "import/pool5/".
How can I tell my graph that don't want to use his input "images", but the tensor "import/pool5/" as input ?
Thank's !
EDIT
OK I realize I haven't been very clear. Here is the situation:
I am trying to use this implementation of ROI pooling, using a pre-trained VGG16, which I have in the GraphDef format. So here is what I do:
First of all, I load the model:
tf.reset_default_graph()
with open("tensorflow-vgg16/vgg16.tfmodel",
mode='rb') as f:
fileContent = f.read()
graph_def = tf.GraphDef()
graph_def.ParseFromString(fileContent)
graph = tf.get_default_graph()
Then, I create my placeholders
images = tf.placeholder(tf.float32,
[None, 448, 448, 3],
name="images") #batch x width x height x channels
boxes = tf.placeholder(tf.float32,
[None,5], # 5 = [batch_id,x1,y1,x2,y2]
name = "boxes")
And I define the output of the first part of the graph to be conv5_3/Relu
tf.import_graph_def(graph_def,
input_map={'images':images})
out_tensor = graph.get_tensor_by_name("import/conv5_3/Relu:0")
So, out_tensor is of shape [None,14,14,512]
Then, I do the ROI pooling:
[out_pool,argmax] = module.roi_pool(out_tensor,
boxes,
7,7,1.0/1)
With out_pool.shape = N_Boxes_in_batch x 7 x 7 x 512, which is homogeneous to pool5. I would then like to feed out_pool as an input to the op that comes just after pool5, so it would look like
tf.import_graph_def(graph.as_graph_def(),
input_map={'import/pool5':out_pool})
But it doesn't work, I have this error:
---------------------------------------------------------------------------
TypeError Traceback (most recent call last)
<ipython-input-89-527398d7344b> in <module>()
5
6 tf.import_graph_def(graph.as_graph_def(),
----> 7 input_map={'import/pool5':out_pool})
8
9 final_out = graph.get_tensor_by_name("import/Relu_1:0")
/usr/local/lib/python3.4/dist-packages/tensorflow/python/framework/importer.py in import_graph_def(graph_def, input_map, return_elements, name, op_dict)
333 # NOTE(mrry): If the graph contains a cycle, the full shape information
334 # may not be available for this op's inputs.
--> 335 ops.set_shapes_for_outputs(op)
336
337 # Apply device functions for this op.
/usr/local/lib/python3.4/dist-packages/tensorflow/python/framework/ops.py in set_shapes_for_outputs(op)
1610 raise RuntimeError("No shape function registered for standard op: %s"
1611 % op.type)
-> 1612 shapes = shape_func(op)
1613 if len(op.outputs) != len(shapes):
1614 raise RuntimeError(
/home/hbenyounes/vqa/roi_pooling_op_grad.py in _roi_pool_shape(op)
13 channels = dims_data[3]
14 print(op.inputs[1].name, op.inputs[1].get_shape())
---> 15 dims_rois = op.inputs[1].get_shape().as_list()
16 num_rois = dims_rois[0]
17
/usr/local/lib/python3.4/dist-packages/tensorflow/python/framework/tensor_shape.py in as_list(self)
745 A list of integers or None for each dimension.
746 """
--> 747 return [dim.value for dim in self._dims]
748
749 def as_proto(self):
TypeError: 'NoneType' object is not iterable
Any clue ?
What I would do is something along those lines:
-First retrieve the names of the tensors representing the weights and biases of the 3 fully connected layers coming after pool5 in VGG16.
To do that I would inspect [n.name for n in graph.as_graph_def().node].
(They probably look something like import/locali/weight:0, import/locali/bias:0, etc.)
-Put them in a python list:
weights_names=["import/local1/weight:0" ,"import/local2/weight:0" ,"import/local3/weight:0"]
biases_names=["import/local1/bias:0" ,"import/local2/bias:0" ,"import/local3/bias:0"]
-Define a function that look something like:
def pool5_tofcX(input_tensor, layer_number=3):
flatten=tf.reshape(input_tensor,(-1,7*7*512))
tmp=flatten
for i in xrange(layer_number):
tmp=tf.matmul(tmp, graph.get_tensor_by_name(weights_name[i]))
tmp=tf.nn.bias_add(tmp, graph.get_tensor_by_name(biases_name[i]))
tmp=tf.nn.relu(tmp)
return tmp
Then define the tensor using the function:
wanted_output=pool5_tofcX(out_pool)
Then you are done !
It is usually very convenient to use tf.train.export_meta_graph to store the whole MetaGraph. Then, upon restoring you can use tf.train.import_meta_graph, because it turns out that it passes all additional arguments to the underlying import_scoped_meta_graph which has the input_map argument and utilizes it when it gets to it's own invocation of import_graph_def.
It is not documented, and took me waaaay toooo much time to find it, but it works!
Jonan Georgiev provided an excellent answer here. The same approach was also described with little fanfare at the end of this git issue: https://github.com/tensorflow/tensorflow/issues/3389
Below is a copy/paste runnable example of using this approach to switch out a placeholder for a tf.data.Dataset get_next tensor.
import tensorflow as tf
my_placeholder = tf.placeholder(dtype=tf.float32, shape=1, name='my_placeholder')
my_op = tf.square(my_placeholder, name='my_op')
# Save the graph to memory
graph_def = tf.get_default_graph().as_graph_def()
print('----- my_op before any remapping -----')
print([n for n in graph_def.node if n.name == 'my_op'])
tf.reset_default_graph()
ds = tf.data.Dataset.from_tensors(1.0)
next_tensor = tf.data.make_one_shot_iterator(ds).get_next(name='my_next_tensor')
# Restore the graph with a custom input mapping
tf.graph_util.import_graph_def(graph_def, input_map={'my_placeholder': next_tensor}, name='')
print('----- my_op after remapping -----')
print([n for n in tf.get_default_graph().as_graph_def().node if n.name == 'my_op'])
Output, where we can clearly see that the input to the square operation has changed.
----- my_op before any remapping -----
[name: "my_op"
op: "Square"
input: "my_placeholder"
attr {
key: "T"
value {
type: DT_FLOAT
}
}
]
----- my_op after remapping -----
[name: "my_op"
op: "Square"
input: "my_next_tensor"
attr {
key: "T"
value {
type: DT_FLOAT
}
}
]
来源：https://stackoverflow.com/questions/38618960/tensorflow-how-to-insert-custom-input-to-existing-graph