TensorFlow Object Detection API print objects found on image to console

I'm trying to return list of objects that have been found at image with TF Object Detection API.

To do that I'm using print([category_index.get(i) for i in classes[0]]) to print list of objects that have been found or print(num_detections) to display number of found objects, but in both cases it gives me list with 300 values or simply value [300.] correspondingly.

How it`s possible to return only that objects that are on image? Or if there is some mistake please help to figure out what is wrong.

I was using Faster RCNN models config file and checkpoints while training. Be sure it really detects few objects at image, here it is:

My code:

import numpy as np
import os
import six.moves.urllib as urllib
import sys
import tarfile
import tensorflow as tf
import zipfile

from collections import defaultdict
from io import StringIO
from matplotlib import pyplot as plt
from PIL import Image

from object_detection.utils import label_map_util
from object_detection.utils import visualization_utils as vis_util

PATH_TO_CKPT = 'frozen_graph/frozen_inference_graph.pb'

PATH_TO_LABELS = 'object_detection/pascal_label_map.pbtxt'

NUM_CLASSES = 7

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='')

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)

def load_image_into_numpy_array(image):
  (im_width, im_height) = image.size
  return np.array(image.getdata()).reshape(
      (im_height, im_width, 3)).astype(np.uint8)


PATH_TO_TEST_IMAGES_DIR = 'object_detection/test_images/'
TEST_IMAGE_PATHS = [ os.path.join(PATH_TO_TEST_IMAGES_DIR, 'image{}.jpg'.format(i)) for i in range(1, 2) ]

IMAGE_SIZE = (12, 8)

with detection_graph.as_default():
  with tf.Session(graph=detection_graph) as sess:
    sess.run(tf.global_variables_initializer())
    img = 1
    for image_path in TEST_IMAGE_PATHS:
      image = Image.open(image_path)
      image_np = load_image_into_numpy_array(image)
      # Expand dimensions since the model expects images to have shape: [1, None, None, 3]
      image_np_expanded = np.expand_dims(image_np, axis=0)
      image_tensor = detection_graph.get_tensor_by_name('image_tensor:0')
      # Each box represents a part of the image where a particular object was detected.
      boxes = detection_graph.get_tensor_by_name('detection_boxes:0')
      scores = detection_graph.get_tensor_by_name('detection_scores:0')
      classes = detection_graph.get_tensor_by_name('detection_classes:0')
      num_detections = detection_graph.get_tensor_by_name('num_detections:0')

      (boxes, scores, classes, num_detections) = sess.run(
          [boxes, scores, classes, num_detections],
          feed_dict={image_tensor: image_np_expanded})

      vis_util.visualize_boxes_and_labels_on_image_array(
          image_np,
          np.squeeze(boxes),
          np.squeeze(classes).astype(np.int32),
          np.squeeze(scores),
          category_index,
          use_normalized_coordinates=True,
          line_thickness=8)
      plt.figure(figsize=IMAGE_SIZE)
      plt.imsave('RESULTS/' + str(img) + '.jpg', image_np)
      img += 1

      # Return found objects
      print([category_index.get(i) for i in classes[0]])
      print(boxes.shape)
      print(num_detections)

Which gives following result:

[{'name': 'marlboro_red', 'id': 7}, {'name': 'marlboro_red', 'id': 7}, {'name': 'marlboro_red', 'id': 7}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'marlboro_red', 'id': 7}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'marlboro_red', 'id': 7}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'marlboro_red', 'id': 7}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'marlboro_red', 'id': 7}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'marlboro_red', 'id': 7}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'marlboro_red', 'id': 7}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'marlboro_red', 'id': 7}, {'name': 'marlboro_red', 'id': 7}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'marlboro_red', 'id': 7}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'marlboro_red', 'id': 7}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'marlboro_red', 'id': 7}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'marlboro_red', 'id': 7}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'marlboro_red', 'id': 7}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'marlboro_red', 'id': 7}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'marlboro_red', 'id': 7}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'marlboro_red', 'id': 7}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'marlboro_red', 'id': 7}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'marlboro_red', 'id': 7}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'marlboro_red', 'id': 7}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'marlboro_red', 'id': 7}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'marlboro_red', 'id': 7}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'marlboro_red', 'id': 7}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'marlboro_red', 'id': 7}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'marlboro_red', 'id': 7}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'marlboro_red', 'id': 7}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'marlboro_red', 'id': 7}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'marlboro_red', 'id': 7}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'marlboro_red', 'id': 7}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'marlboro_red', 'id': 7}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'marlboro_red', 'id': 7}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'marlboro_red', 'id': 7}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'marlboro_red', 'id': 7}, {'name': 'marlboro_red', 'id': 7}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'marlboro_red', 'id': 7}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'marlboro_red', 'id': 7}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'marlboro_red', 'id': 7}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'marlboro_red', 'id': 7}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'marlboro_red', 'id': 7}, {'name': 'marlboro_red', 'id': 7}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'marlboro_red', 'id': 7}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'marlboro_red', 'id': 7}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'marlboro_red', 'id': 7}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'chesterfield_blue', 'id': 1}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'marlboro_gold', 'id': 5}, {'name': 'marlboro_red', 'id': 7}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'marlboro_red', 'id': 7}, {'name': 'chesterfield_red', 'id': 2}, {'name': 'marlboro_red', 'id': 7}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'marlboro_red', 'id': 7}, {'name': 'lucky_strike_blue', 'id': 3}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'lucky_strike_red', 'id': 4}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'marlboro_mentol', 'id': 6}, {'name': 'lucky_strike_red', 'id': 4}]
(1, 300, 4)
[ 300.]

Thanks in advance for any information!

UPD:

Thousand thanks for everyone who helped with this question. Following line of code is exactly what I needed, it gives me list with objects that were found so I can do other operations on them.

print [category_index.get(value) for index,value in enumerate(classes[0]) if scores[0,index] > 0.5]