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I created an object detection model on Azure Microsoft custom vision for satellite images( ship Dataset) ,then I exported a model by docker file and I get a zip file inside it 2 docker files (app and Azureml) inside docker file (app) there are 5 files ( app.py, labels.pbtxt, model.pb, object_detection.py, predict.py). Then I used to program uses a TensorFlow-trained classifier to perform object detection, it loads the classifier uses it to perform object detection on a video and It draws boxes and scores around the objects of interest in each frame of the video. So, I implement this program on collab and I gave it a path of my model(.pb) that I exported and labels(.txt) that I converted to (.pbtxt) with one item class Ship, and path of video that I want to do on it a detection and everything works well until I arrived to :

# Define input and output tensors (i.e. data) for the object detection classifier

# Input tensor is the image
image_tensor = detection_graph.get_tensor_by_name('image_tensor:0')

# Output tensors are the detection boxes, scores, and classes
# Each box represents a part of the image where a particular object was detected
detection_boxes = detection_graph.get_tensor_by_name('detection_boxes:0')

# Each score represents level of confidence for each of the objects.
# The score is shown on the result image, together with the class label.
detection_scores = detection_graph.get_tensor_by_name('detection_scores:0')
detection_classes = detection_graph.get_tensor_by_name('detection_classes:0')

# Number of objects detected
num_detections = detection_graph.get_tensor_by_name('num_detections:0')

I tried to open a (predict.py, object_detection.py and app.py) to see what is an equivalent name of each of these: image_tensor:0,detection_boxes:0,........ I just find the equal of image_tensor:0 --> model_output:0. I didn't find the other names, please someone can help me to finish this and arrive to detect ships from the video.

This is all code:

# Import packages

import os
import cv2
import numpy as np
import tensorflow as tf
import sys

# This is needed since the notebook is stored in the object_detection folder.
sys.path.append("..")

# Import utilites
from utils import label_map_util
from utils import visualization_utils as vis_util

# Name of the directory containing the object detection module we're using
MODEL_NAME = 'inference_graph'
VIDEO_NAME = 'test.mov'

# Grab path to current working directory
CWD_PATH = os.getcwd()

# Path to frozen detection graph .pb file, which contains the model that is used
# for object detection.
PATH_TO_CKPT = os.path.join(CWD_PATH,MODEL_NAME,'frozen_inference_graph.pb')

# Path to label map file
PATH_TO_LABELS = os.path.join(CWD_PATH,'training','labelmap.pbtxt')

# Path to video
PATH_TO_VIDEO = os.path.join(CWD_PATH,VIDEO_NAME)

# Number of classes the object detector can identify
NUM_CLASSES = 6

# Load the label map.
# Label maps map indices to category names, so that when our convolution
# network predicts `5`, we know that this corresponds to `king`.
# Here we use internal utility functions, but anything that returns a
# dictionary mapping integers to appropriate string labels would be fine
label_map = label_map_util.load_labelmap(PATH_TO_LABELS)
categories = label_map_util.convert_label_map_to_categories(label_map, max_num_classes=NUM_CLASSES, use_display_name=True)
category_index = label_map_util.create_category_index(categories)

# Load the Tensorflow model into memory.
detection_graph = tf.Graph()
with detection_graph.as_default():
    od_graph_def = tf.GraphDef()
    with tf.gfile.GFile(PATH_TO_CKPT, 'rb') as fid:
        serialized_graph = fid.read()
        od_graph_def.ParseFromString(serialized_graph)
        tf.import_graph_def(od_graph_def, name='')

    sess = tf.Session(graph=detection_graph)

# Define input and output tensors (i.e. data) for the object detection classifier

# Input tensor is the image
image_tensor = detection_graph.get_tensor_by_name('image_tensor:0')

# Output tensors are the detection boxes, scores, and classes
# Each box represents a part of the image where a particular object was detected
detection_boxes = detection_graph.get_tensor_by_name('detection_boxes:0')

# Each score represents level of confidence for each of the objects.
# The score is shown on the result image, together with the class label.
detection_scores = detection_graph.get_tensor_by_name('detection_scores:0')
detection_classes = detection_graph.get_tensor_by_name('detection_classes:0')

# Number of objects detected
num_detections = detection_graph.get_tensor_by_name('num_detections:0')

# Open video file
video = cv2.VideoCapture(PATH_TO_VIDEO)

while(video.isOpened()):

    # Acquire frame and expand frame dimensions to have shape: [1, None, None, 3]
    # i.e. a single-column array, where each item in the column has the pixel RGB value
    ret, frame = video.read()
    frame_expanded = np.expand_dims(frame, axis=0)

    # Perform the actual detection by running the model with the image as input
    (boxes, scores, classes, num) = sess.run(
        [detection_boxes, detection_scores, detection_classes, num_detections],
        feed_dict={image_tensor: frame_expanded})

    # Draw the results of the detection (aka 'visulaize the results')
    vis_util.visualize_boxes_and_labels_on_image_array(
        frame,
        np.squeeze(boxes),
        np.squeeze(classes).astype(np.int32),
        np.squeeze(scores),
        category_index,
        use_normalized_coordinates=True,
        line_thickness=8,
        min_score_thresh=0.80)

    # All the results have been drawn on the frame, so it's time to display it.
    cv2.imshow('Object detector', frame)

    # Press 'q' to quit
    if cv2.waitKey(1) == ord('q'):
        break

# Clean up
video.release()
cv2.destroyAllWindows()
Masoud Rahimi
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R.Faiza
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  • What is your question then? Do you mean where those variable names come from? If that is the question, then the answer is: Names like `image_tensor:0` are all defined in tensorflow computation graph. The `.pb` contains all graph definition variables and corresponding weights so that you can directory load them to perform inference. `detection_graph.get_tensor_by_name('image_tensor:0')` tells you that there is a tensor named `image_tensor:0` in the graph. – Danny Fang May 08 '19 at 15:14
  • no i didn't mean where those variables names come from . the problem that those names in definition they are not matched by names of my model created on Microsoft custom vision . for example 'image_tensor:0' equivalent to 'model_output:0' but how can i know the other names (boxes,classes,scores,.....) – R.Faiza May 09 '19 at 12:56
  • But it appears strange to me that `image_tensor:0` is an input placeholder node, how is that equal to `model_output:0`? This does not make sense – Danny Fang May 09 '19 at 13:05
  • May you specify why you want to find equivalent names of those names? Because from my perspective that your code should work fine. – Danny Fang May 09 '19 at 13:11

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