Problems loading TensorFlow model in C++

crackwitz · July 9, 2023, 11:42am

if you think updating the library would help, then do it. you don’t need to ask.

github.com/opencv/opencv

Load TensorFlow 2 model (SSD, Object Detection API) with OpenCV

opened 04:24PM - 04 Jan 21 UTC

closed 08:55AM - 03 Feb 21 UTC

golden96371

feature category: dnn

##### System information (version) - OpenCV => 4.5.1 (python) - TensorFlow => …2.3.1 (python) - Operating System / Platform => Windows 10 (64 Bit) - Compiler => Visual Studio 2019 ##### Detailed description After training a SSD MobileNet v2 using the TensorFlow Object Detection API with TensorFlow2, I converted the SavedModel into a FrozenGraph in order to make it compatible with OpenCV. I am using following code to load the model: ``` python import numpy as np import cv2 as cv net = cv.dnn.readNet('frozen_graph.pb') ``` This gives following error message: ``` Traceback (most recent call last): File "<stdin>", line 1, in <module> cv2.error: OpenCV(4.5.1) C:\Users\appveyor\AppData\Local\Temp\1\pip-req-build-oduouqig\opencv\modules\dnn\src\tensorflow\tf_importer.cpp:578: error: (-2:Unspecified error) More than one input is Const op in function 'cv::dnn::dnn4_v20201117::`anonymous-namespace'::TFImporter::getConstBlob' ``` The script `opencv/tf_text_graph_ssd.py` runs into an assertion: ``` Traceback (most recent call last): File "tf_text_graph_ssd_original.py", line 405, in <module> createSSDGraph(args.input, args.config, args.output) File "tf_text_graph_ssd_original.py", line 292, in createSSDGraph assert(num_matched_layers == num_layers) AssertionError ``` After fixing the assertion by adapting the layer names in the script, the text graph could be created. After loading the model with ``` python net = cv.dnn.readNet('frozen_graph.pb', 'graph.pbtxt') ``` there is a different error message ``` Traceback (most recent call last): File "<stdin>", line 1, in <module> cv2.error: OpenCV(4.5.1) C:\Users\appveyor\AppData\Local\Temp\1\pip-req-build-oduouqig\opencv\modules\dnn\src\tensorflow\tf_graph_simplifier.cpp:1019: error: (-215:Assertion failed) permIds.size() == net.node_size() in function 'cv::dnn::dnn4_v20201117::sortByExecutionOrder' ``` I attach my frozen_graph.pb and my pipeline.config. [model.zip](https://github.com/opencv/opencv/files/5765665/model.zip) ##### Steps to reproduce 1.) Train a SSD MobileNet v2 using the [TensorFlow Object Detection API](https://github.com/tensorflow/models/tree/master/research/object_detection) and export it to a SavedModel ``` # Train the network python model_main_tf2.py --model_dir="training" --pipeline_config_path="training/pipeline.config" # Export the network python exporter_main_v2.py --input_type=image_tensor --pipeline_config_path="training/pipeline.config" --trained_checkpoint_dir="training" --output_directory="training/model" ``` 2.) Convert the SavedModel to a FrozenGraph ``` python import tensorflow as tf from tensorflow.python.framework.convert_to_constants import convert_variables_to_constants_v2 loaded = tf.saved_model.load('training/model/saved_model') infer = loaded.signatures['serving_default'] f = tf.function(infer).get_concrete_function(input_tensor=tf.TensorSpec(shape=[1, None, None, 3], dtype=tf.uint8)) f2 = convert_variables_to_constants_v2(f) graph_def = f2.graph.as_graph_def() # Export frozen graph with tf.io.gfile.GFile('frozen_graph.pb', 'wb') as f: f.write(graph_def.SerializeToString()) ``` 3.) Try to load the FrozenGraph with OpenCV as described above: failed Anyone can reproduce the issue and help me to fix it?

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Problems loading TensorFlow model in C++

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