tensorflow checkpoint missing input tensor node - github

Question

( please pardon my long post, dearly appreciate your help )
I am training the squeezeDet model for the pascal VOC style custom data as per the training code from the repository HERE
train.py
model_definition and HERE
the saved model checkpoint performs well as I can see acceptable performance.
Now i am trying to freeze the model for deployment using coreML to see how the performance is in a mobile platform. The authors of the script only report performance in a GPU environment in their research paper.
I follow the recommended steps as per tensorflow, my commands are as below
First,
I write the graph out from the checkpoint meta file
path_to_ckpt_meta = rootdir + "model.ckpt-355000.meta"
path_to_ckpt_data = rootdir + "model.ckpt-355000"
sess = tf.Session(config=tf.ConfigProto(allow_soft_placement=True))
saver = tf.train.import_meta_graph(path_to_ckpt_meta)
saver.restore(sess, path_to_ckpt_data)
tf.train.write_graph(tf.get_default_graph().as_graph_def(), rootdir, "model_ckpt_355000_graph_V2.pb", False)
Now
I check the graph summary as see all the tensors in the model . The output summary file is HERE.
However, when I check the checkpoint file using the inspect_checkpoint.py function from tensorflow I see no image_input nodes. The output of inspection is HERE.
Second
I freeze the graph using the tensorflow freeze_graph.py function
python ./tensorflow/python/tools/freeze_graph.py \
--input_graph=path-to-dir/train/model_ckpt_355000_graph.pb \
--input_checkpoint=path-to-dir/train/model.ckpt-355000 \
--output_graph=path-to-dir/train/frozen_sqdt_ckpt_355000.pb \
--output_node_names=bbox/trimming/bbox,probability/score,probability/class_idx
the freeze_graph call completes without error and results in the frozen graph as per the command above.
Now,
when I check the frozen graph using the summarize_graph function call
bazel-bin/tensorflow/tools/graph_transforms/summarize_graph --in_graph=/tmp/logs/squeezeDet_NewDataset_test01_March02/train/frozen_sqdt_ckpt_355000.pb
I get the following
No inputs spotted.
No variables spotted.
Found 3 possible outputs: (name=bbox/trimming/bbox, op=Transpose) (name=probability/score, op=Max) (name=probability/class_idx, op=ArgMax)
Found 2703452 (2.70M) const parameters, 0 (0) variable parameters, and 0 control_edges
Op types used: 130 Const, 68 Identity, 32 BiasAdd, 32 Conv2D, 31 Relu, 15 Mul, 14 Add, 10 ConcatV2, 9 Sub, 5 RealDiv, 5 Reshape, 4 Maximum, 4 Minimum, 3 StridedSlice, 3 MaxPool, 2 Exp, 2 Greater, 2 Cast, 2 Select, 1 Transpose, 1 Softmax, 1 Sigmoid, 1 Unpack, 1 RandomUniform, 1 QueueDequeueManyV2, 1 Pack, 1 Max, 1 Floor, 1 FIFOQueueV2, 1 ArgMax
To use with tensorflow/tools/benchmark:benchmark_model try these arguments:
bazel run tensorflow/tools/benchmark:benchmark_model -- --graph=/tmp/logs/squeezeDet_NewDataset_test01_March02/train/frozen_sqdt_ckpt_355000.pb --show_flops --input_layer= --input_layer_type= --input_layer_shape= --output_layer=bbox/trimming/bbox,probability/score,probability/class_idx
this output above suggests that there is no input detected from the frozen graph. I check the summary of the frozen graph and find no image_input tensor. HERE
When I check my original graph ( written in step 1 ) with summarize graph, It does show inputs.
My troubleshooting
Suggests there is some mixup in the original authors code where the image_input is not provided as an input tensor. Though, the confusing part is that I can see the input image tensor in the summary of the output graph from the checkpoint meta file.
My question is,
-- why is the frozen graph removing the input nodes, when the original graph has the inputs ?
-- And, what can I do to change this and be able to successfully freeze_graph correctly.
Is there a transformation that need to perform in order to make this freeze model compatible with the coreML format.?
All your help is much appreciated.
Best
Aman