Skip to content

Instantly share code, notes, and snippets.

What would you like to do?
Track any object in a video with Dlib Correlation Trackers. Tutorial:
Using Correlation Trackers in Dlib, you can track any object in a video stream without needing to train a custom object detector.
Check out the tutorial at:
import numpy as np
import cv2
import dlib
# this variable will hold the coordinates of the mouse click events.
mousePoints = []
def mouseEventHandler(event, x, y, flags, param):
# references to the global mousePoints variable
global mousePoints
# if the left mouse button was clicked, record the starting coordinates.
if event == cv2.EVENT_LBUTTONDOWN:
mousePoints = [(x, y)]
# when the left mouse button is released, record the ending coordinates.
elif event == cv2.EVENT_LBUTTONUP:
mousePoints.append((x, y))
# create the video capture.
video_capture = cv2.VideoCapture(0)
# create a named window in OpenCV and attach the mouse event handler to it.
cv2.namedWindow("Webcam stream")
cv2.setMouseCallback("Webcam stream", mouseEventHandler)
# initialize the correlation tracker.
tracker = dlib.correlation_tracker()
# this is the variable indicating whether to track the object or not.
tracked = False
while True:
# start capturing the video stream.
ret, frame =
if ret:
image = frame
# if we have two sets of coordinates from the mouse event, draw a rectangle.
if len(mousePoints) == 2:
cv2.rectangle(image, mousePoints[0], mousePoints[1], (0, 255, 0), 2)
dlib_rect = dlib.rectangle(mousePoints[0][0], mousePoints[0][1], mousePoints[1][0], mousePoints[1][1])
# tracking in progress, update the correlation tracker and get the object position.
if tracked == True:
track_rect = tracker.get_position()
x = int(track_rect.left())
y = int(
x1 = int(track_rect.right())
y1 = int(track_rect.bottom())
cv2.rectangle(image, (x, y), (x1, y1), (0, 0, 255), 2)
# show the current frame.
cv2.imshow("Webcam stream", image)
# capture the keyboard event in the OpenCV window.
ch = 0xFF & cv2.waitKey(1)
# press "r" to stop tracking and reset the points.
if ch == ord("r"):
mousePoints = []
tracked = False
# press "t" to start tracking the currently selected object/area.
if ch == ord("t"):
if len(mousePoints) == 2:
tracker.start_track(image, dlib_rect)
tracked = True
mousePoints = []
# press "q" to quit the program.
if ch == ord('q'):
# cleanup.
Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
You can’t perform that action at this time.