TensorFlow Object Detection API示例

导入必要的基础库


In [1]:
import os
import cv2
import time
import argparse
import multiprocessing
import numpy as np
import tensorflow as tf
from matplotlib import pyplot as plt
%matplotlib inline

从TF Object Detection API中导入必要的模块


In [2]:
from object_detection.utils import label_map_util
from object_detection.utils import visualization_utils as vis_util

定义所使用预训练模型


In [3]:
CWD_PATH = os.getcwd()

# Path to frozen detection graph. This is the actual model that is used for the object detection.
MODEL_NAME = 'ssd_mobilenet_v1_coco_11_06_2017'
PATH_TO_CKPT = os.path.join(CWD_PATH, 'object_detection', MODEL_NAME, 'frozen_inference_graph.pb')

# List of the strings that is used to add correct label for each box.
PATH_TO_LABELS = os.path.join(CWD_PATH, 'object_detection', 'data', 'mscoco_label_map.pbtxt')

定义基础类别与载入数据


In [4]:
NUM_CLASSES = 90

# Loading label map
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)

定义检测函数


In [5]:
def detect_objects(image_np, sess, detection_graph):
    # 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')

    # Each score represent how level of confidence for each of the objects.
    # Score is shown on the result image, together with the class label.
    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')

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

    # Visualization of the results of a detection.
    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)
    return image_np

准备示例1: 图片中的物体检测


In [6]:
# First test on images
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, 3) ]

# Size, in inches, of the output images.
IMAGE_SIZE = (12, 8)

In [7]:
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)

In [8]:
from PIL import Image
for image_path in TEST_IMAGE_PATHS:
    image = Image.open(image_path)
    image_np = load_image_into_numpy_array(image)
    plt.imshow(image_np)
    print(image.size, image_np.shape)


(1024, 636) (636, 1024, 3)
(1352, 900) (900, 1352, 3)

载入预训练的TF模型


In [9]:
#Load a frozen TF model 
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='')

在样例图片上进行检测


In [10]:
with detection_graph.as_default():
    with tf.Session(graph=detection_graph) as sess:
        for image_path in TEST_IMAGE_PATHS:
            image = Image.open(image_path)
            image_np = load_image_into_numpy_array(image)
            image_process = detect_objects(image_np, sess, detection_graph)
            print(image_process.shape)
            plt.figure(figsize=IMAGE_SIZE)
            plt.imshow(image_process)


(636, 1024, 3)
(900, 1352, 3)

准备示例2: 视频中的物体检测


In [11]:
# Import everything needed to edit/save/watch video clips
from moviepy.editor import VideoFileClip
from IPython.display import HTML

In [12]:
def process_image(image):
    # NOTE: The output you return should be a color image (3 channel) for processing video below
    # you should return the final output (image with lines are drawn on lanes)
    with detection_graph.as_default():
        with tf.Session(graph=detection_graph) as sess:
            image_process = detect_objects(image, sess, detection_graph)
            return image_process

In [13]:
white_output = 'video1_out.mp4'
clip1 = VideoFileClip("video1.mp4").subclip(0,2)
white_clip = clip1.fl_image(process_image) #NOTE: this function expects color images!!s
%time white_clip.write_videofile(white_output, audio=False)


[MoviePy] >>>> Building video video1_out.mp4
[MoviePy] Writing video video1_out.mp4
 97%|█████████▋| 30/31 [00:35<00:01,  1.16s/it]
[MoviePy] Done.
[MoviePy] >>>> Video ready: video1_out.mp4 

CPU times: user 39 s, sys: 3.36 s, total: 42.3 s
Wall time: 36.1 s

In [14]:
HTML("""
<video width="960" height="540" controls>
  <source src="{0}">
</video>
""".format(white_output))


Out[14]:

In [15]:
white_output1 = 'video2_out.mp4'
clip1 = VideoFileClip("video2.mp4").subclip(0,2)
white_clip = clip1.fl_image(process_image) #NOTE: this function expects color images!!s
%time white_clip.write_videofile(white_output1, audio=False)


[MoviePy] >>>> Building video video2_out.mp4
[MoviePy] Writing video video2_out.mp4
 97%|█████████▋| 30/31 [00:34<00:01,  1.15s/it]
[MoviePy] Done.
[MoviePy] >>>> Video ready: video2_out.mp4 

CPU times: user 37.9 s, sys: 3.26 s, total: 41.2 s
Wall time: 35 s

In [16]:
HTML("""
<video width="960" height="540" controls>
  <source src="{0}">
</video>
""".format(white_output1))


Out[16]:

In [17]:
white_output3 = 'video3_out.mp4'
clip3 = VideoFileClip("video3.mp4").subclip(12,14)
white_clip = clip3.fl_image(process_image) #NOTE: this function expects color images!!s
%time white_clip.write_videofile(white_output3, audio=False)


[MoviePy] >>>> Building video video3_out.mp4
[MoviePy] Writing video video3_out.mp4
 97%|█████████▋| 30/31 [00:35<00:01,  1.16s/it]
[MoviePy] Done.
[MoviePy] >>>> Video ready: video3_out.mp4 

CPU times: user 38.9 s, sys: 3.43 s, total: 42.4 s
Wall time: 36.1 s

In [18]:
HTML("""
<video width="960" height="540" controls>
  <source src="{0}">
</video>
""".format(white_output3))


Out[18]:

In [19]:
# Merge videos
from moviepy.editor import VideoFileClip, concatenate_videoclips
clip1 = VideoFileClip("video1_out.mp4")
clip2 = VideoFileClip("video2_out.mp4")
clip3 = VideoFileClip("video3_out.mp4")
final_clip = concatenate_videoclips([clip1,clip2,clip3], method="compose")
final_clip.write_videofile("final_results.mp4",bitrate="5000k")


[MoviePy] >>>> Building video final_results.mp4
[MoviePy] Writing video final_results.mp4
 99%|█████████▉| 90/91 [00:01<00:00, 74.63it/s]
[MoviePy] Done.
[MoviePy] >>>> Video ready: final_results.mp4 


In [20]:
from moviepy.editor import *
clip = VideoFileClip("final_results.mp4")
clip.write_gif("final_results.gif")


[MoviePy] Building file final_results.gif with imageio
 99%|█████████▉| 90/91 [00:19<00:00,  4.45it/s]