401-object-detection-webcam: Live Object Detection with OpenVINO


Thu Jun 16 2022 14:49:51 GMT+0000 (Coordinated Universal Time)

Saved by @OpenVINOtoolkit #python #openvino #openvino-notebooks #live-inference #deeplearning #accelerated-inference #object-detection

# Imports
import collections
import os
import sys
import time

import cv2
import numpy as np
from IPython import display
from openvino.runtime import Core

import notebook_utils as utils

# Download the Model
# directory where model will be downloaded
base_model_dir = "model"

# model name as named in Open Model Zoo
model_name = "ssdlite_mobilenet_v2"

download_command = f"omz_downloader " \
                   f"--name {model_name} " \
                   f"--output_dir {base_model_dir} " \
                   f"--cache_dir {base_model_dir}"
! $download_command

# Convert the Model
precision = "FP16"

# output path for the conversion
converted_model_path = f"model/public/{model_name}/{precision}/{model_name}.xml"

if not os.path.exists(converted_model_path):
    convert_command = f"omz_converter " \
                      f"--name {model_name} " \
                      f"--download_dir {base_model_dir} " \
                      f"--precisions {precision}"
    ! $convert_command

# Load the Model
# initialize inference engine
ie_core = Core()
# read the network and corresponding weights from file
model = ie_core.read_model(model=converted_model_path)
# compile the model for the CPU (you can choose manually CPU, GPU, MYRIAD etc.)
# or let the engine choose the best available device (AUTO)
compiled_model = ie_core.compile_model(model=model, device_name="CPU")

# get input and output nodes
input_layer = compiled_model.input(0)
output_layer = compiled_model.output(0)

# get input size
height, width = list(input_layer.shape)[1:3]

# Process Results
# https://tech.amikelive.com/node-718/what-object-categories-labels-are-in-coco-dataset/
classes = [
    "background", "person", "bicycle", "car", "motorcycle", "airplane", "bus", "train",
    "truck", "boat", "traffic light", "fire hydrant", "street sign", "stop sign",
    "parking meter", "bench", "bird", "cat", "dog", "horse", "sheep", "cow", "elephant",
    "bear", "zebra", "giraffe", "hat", "backpack", "umbrella", "shoe", "eye glasses",
    "handbag", "tie", "suitcase", "frisbee", "skis", "snowboard", "sports ball", "kite",
    "baseball bat", "baseball glove", "skateboard", "surfboard", "tennis racket", "bottle",
    "plate", "wine glass", "cup", "fork", "knife", "spoon", "bowl", "banana", "apple",
    "sandwich", "orange", "broccoli", "carrot", "hot dog", "pizza", "donut", "cake", "chair",
    "couch", "potted plant", "bed", "mirror", "dining table", "window", "desk", "toilet",
    "door", "tv", "laptop", "mouse", "remote", "keyboard", "cell phone", "microwave", "oven",
    "toaster", "sink", "refrigerator", "blender", "book", "clock", "vase", "scissors",
    "teddy bear", "hair drier", "toothbrush", "hair brush"

# colors for above classes (Rainbow Color Map)
colors = cv2.applyColorMap(
    src=np.arange(0, 255, 255 / len(classes), dtype=np.float32).astype(np.uint8),

def process_results(frame, results, thresh=0.6):
    # size of the original frame
    h, w = frame.shape[:2]
    # results is a tensor [1, 1, 100, 7]
    results = results.squeeze()
    boxes = []
    labels = []
    scores = []
    for _, label, score, xmin, ymin, xmax, ymax in results:
        # create a box with pixels coordinates from the box with normalized coordinates [0,1]
            tuple(map(int, (xmin * w, ymin * h, (xmax - xmin) * w, (ymax - ymin) * h)))

    # apply non-maximum suppression to get rid of many overlapping entities
    # see https://paperswithcode.com/method/non-maximum-suppression
    # this algorithm returns indices of objects to keep
    indices = cv2.dnn.NMSBoxes(
        bboxes=boxes, scores=scores, score_threshold=thresh, nms_threshold=0.6

    # if there are no boxes
    if len(indices) == 0:
        return []

    # filter detected objects
    return [(labels[idx], scores[idx], boxes[idx]) for idx in indices.flatten()]

def draw_boxes(frame, boxes):
    for label, score, box in boxes:
        # choose color for the label
        color = tuple(map(int, colors[label]))
        # draw box
        x2 = box[0] + box[2]
        y2 = box[1] + box[3]
        cv2.rectangle(img=frame, pt1=box[:2], pt2=(x2, y2), color=color, thickness=3)

        # draw label name inside the box
            text=f"{classes[label]} {score:.2f}",
            org=(box[0] + 10, box[1] + 30),
            fontScale=frame.shape[1] / 1000,

    return frame

# Main Processing Function
# main processing function to run object detection
def run_object_detection(source=0, flip=False, use_popup=False, skip_first_frames=0):
    player = None
        # create video player to play with target fps
        player = utils.VideoPlayer(
            source=source, flip=flip, fps=30, skip_first_frames=skip_first_frames
        # start capturing
        if use_popup:
            title = "Press ESC to Exit"
                winname=title, flags=cv2.WINDOW_GUI_NORMAL | cv2.WINDOW_AUTOSIZE

        processing_times = collections.deque()
        while True:
            # grab the frame
            frame = player.next()
            if frame is None:
                print("Source ended")
            # if frame larger than full HD, reduce size to improve the performance
            scale = 1280 / max(frame.shape)
            if scale < 1:
                frame = cv2.resize(

            # resize image and change dims to fit neural network input
            input_img = cv2.resize(
                src=frame, dsize=(width, height), interpolation=cv2.INTER_AREA
            # create batch of images (size = 1)
            input_img = input_img[np.newaxis, ...]

            # measure processing time

            start_time = time.time()
            # get results
            results = compiled_model([input_img])[output_layer]
            stop_time = time.time()
            # get poses from network results
            boxes = process_results(frame=frame, results=results)

            # draw boxes on a frame
            frame = draw_boxes(frame=frame, boxes=boxes)

            processing_times.append(stop_time - start_time)
            # use processing times from last 200 frames
            if len(processing_times) > 200:

            _, f_width = frame.shape[:2]
            # mean processing time [ms]
            processing_time = np.mean(processing_times) * 1000
            fps = 1000 / processing_time
                text=f"Inference time: {processing_time:.1f}ms ({fps:.1f} FPS)",
                org=(20, 40),
                fontScale=f_width / 1000,
                color=(0, 0, 255),

            # use this workaround if there is flickering
            if use_popup:
                cv2.imshow(winname=title, mat=frame)
                key = cv2.waitKey(1)
                # escape = 27
                if key == 27:
                # encode numpy array to jpg
                _, encoded_img = cv2.imencode(
                    ext=".jpg", img=frame, params=[cv2.IMWRITE_JPEG_QUALITY, 100]
                # create IPython image
                i = display.Image(data=encoded_img)
                # display the image in this notebook
    # ctrl-c
    except KeyboardInterrupt:
    # any different error
    except RuntimeError as e:
        if player is not None:
            # stop capturing
        if use_popup:

# Run Live Object Detection
run_object_detection(source=0, flip=True, use_popup=False)

# Run Object Detection on a Video File
video_file = "../201-vision-monodepth/data/Coco Walking in Berkeley.mp4"

run_object_detection(source=video_file, flip=False, use_popup=False)

Object detection finds predefined objects in an image or video. Each returned object includes features such as label, probability and bounding box coordinates relative to image boundaries. List of predefined objects available in this demo: person, bicycle, car, motorcycle, airplane, bus, train, truck, boat, traffic light, fire hydrant, stop sign, parking meter, bench, bird, cat, dog, horse, sheep, cow, elephant, bear, zebra, giraffe, backpack, umbrella, handbag, tie, suitcase, frisbee, skis, snowboard, sports ball, kite, baseball bat, baseball glove, skateboard, surfboard, tennis racket, bottle, wine glass, cup, fork, knife, spoon, bowl, banana, apple, sandwich, orange, broccoli, carrot, hot dog, pizza, donut, cake, chair, couch, potted plant, be, dining table, toilet, tv, laptop, mouse, remote, keyboard, cell phone, microwave, oven, toaster, sink, refrigerator, book, clock, vase, scissors, teddy bear, hair drier, toothbrush. This notebook demonstrates live object detection with OpenVINO. We use the SSDLite MobileNetV2 from Open Model Zoo. At the bottom of this notebook, you will see live inference results from your webcam. You can also upload a video file. If you have not yet installed OpenVINO™, please follow the Installation Guide to install all required dependencies. https://github.com/openvinotoolkit/openvino_notebooks/blob/main/README.md#-installation-guide Link to .bin and .xml files: https://github.com/openvinotoolkit/open_model_zoo/blob/master/models/public/ssdlite_mobilenet_v2/model.yml