opencv: Error Loading .pb model from readNetFromTensorflow

• OpenCV => 3.4
• Operating System / Platform => Windows 64 Bit
• Compiler => Visual Studio 2015

Detailed description

I am making a simple TF model, and it gives me this error: python test.py OpenCV Error: Assertion failed (const_layers.insert(std::make_pair(name, li)).se cond) in cv::dnn::experimental_dnn_v3::anonymous-namespace'::addConstNodes, fil e C:\projects\opencv-python\opencv\modules\dnn\src\tensorflow\tf_importer.cpp, l ine 663 Traceback (most recent call last): File "dnn_test.py", line 4, in <module> cvNet = cv.dnn.readNetFromTensorflow('frozen_graph.pb', 'frozen_graph.pbtxt' ) cv2.error: C:\projects\opencv-python\opencv\modules\dnn\src\tensorflow\tf_import er.cpp:663: error: (-215) const_layers.insert(std::make_pair(name, li)).second i n function cv::dnn::experimental_dnn_v3::anonymous-namespace’::addConstNodes

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the graph as shown below:

    self.x_pl = tf.placeholder(tf.float32, [None,
                                                self.config.img_height,
                                                self.config.img_width,
                                                self.config.num_channels])
    with tf.variable_scope('output') as scope:
        stride = [1, 1, 1, 1]
        kernel_shape = [1,1, self.x_pl.get_shape()[-1], self.config.num_classes]
        w = tf.get_variable('w_conv', kernel_shape, tf.float32,
                            initializer=tf.zeros_initializer())
        self.y_out_unnormal = tf.nn.conv2d(self.x_pl, w, stride, 'SAME')

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and I am saving the model as shown below:

        self.best_saver.save(self.sess, self.config.best_checkpoint_dir, self.model.global_step_tensor)
        tf.train.write_graph(self.sess.graph_def, self.config.best_checkpoint_dir, 'graph.pbtxt', as_text=True)
        tf.train.write_graph(self.sess.graph, self.config.best_checkpoint_dir, 'graph.pb', as_text=False)

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then I frozen the by this command:

        python -m tensorflow.python.tools.freeze_graph --input_binary --input_graph Binary_Protobuf.pb --input_checkpoint mnist_cnn.ckpt --output_graph frozen_graph.pb --output_node_names output/Conv2D

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Then generated the .pbtxt file:

        import tensorflow as tf
        import numpy as np
        graph_filename = "./freez_test/frozen_graph.pb"
        with tf.gfile.GFile(graph_filename, "rb") as f:
            graph_def = tf.GraphDef()
            graph_def.ParseFromString(f.read())
            tf.train.write_graph(graph_def, './', 'frozen_graph.pbtxt', True)

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Then I loaded it to cv python script to see if it is compatible with the library or not:

        import cv2 as cv
        import numpy as np

        cvNet = cv.dnn.readNetFromTensorflow('frozen_graph.pb', 'frozen_graph.pbtxt')

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and it gave me the mentioned error cv::dnn::experimental_dnn_v3::`anonymous-namespace’::addConstNodes

I tested it with much out=x*x graph, and it worked , and this is a simple convolution graph, any one know how to solve this problem?