TLD Implementation in Python With Explanation

#importing cv2 and system package
import cv2
import sys
#So how do you ensure that your code will work no matter which version of OpenCV your production environment is using
# Extract major, minor, and subminor version numbers
(major_ver, minor_ver, subminor_ver) = (cv2.__version__).split('.')
#Every Python module has it’s __name__ defined and if this is ‘__main__’, it implies that the module is being run standalone
#by the user and we can do corresponding appropriate actions.
if __name__ == '__main__' :
    # Set up tracker.
    tracker_type = 'TLD'
    if int(minor_ver) < 3:
        tracker = cv2.Tracker_create(tracker_type)
    else:
        if tracker_type == 'TLD':
            tracker = cv2.TrackerTLD_create()
    # Read video
    video = cv2.VideoCapture("./videos/chaplin.mp4")
    # Exit if video not opened.
    if not video.isOpened():
        print("Could not open video")
        sys.exit()
    # Read first frame.
    ok, frame = video.read()
    if not ok:
        print('Cannot read video file')
        sys.exit()
    #rectangular region of interest (ROI)
    #Let’s start with a sample code. It allows you to select a rectangle in an image,
    #crop the rectangular region and finally display the cropped image.
    bbox = cv2.selectROI(frame, False)
    # Initialize tracker with first frame and bounding box
    ok = tracker.init(frame, bbox)
    file=open("Coordinate.txt","w")
    while True:
        # Read a new frame
        ok, frame = video.read()
        if not ok:
            break
   
        # Start timer
        timer = cv2.getTickCount()
        # Update tracker
        ok, bbox = tracker.update(frame)
        # Calculate Frames per second (FPS)
        fps = cv2.getTickFrequency() / (cv2.getTickCount() - timer);
        frame_count = int(video.get(cv2.CAP_PROP_FRAME_COUNT))
 
        # Draw bounding box
        if ok:
            # Tracking success
            p1 = (int(bbox[0]), int(bbox[1]))
            p2 = (int(bbox[0] + bbox[2]), int(bbox[1] + bbox[3]))
     
            cv2.rectangle(frame, p1, p2, (255,0,0), 2, 1)
        else :
            # Tracking failure
            cv2.putText(frame, "Tracking failure detected", (100,80), cv2.FONT_HERSHEY_SIMPLEX, 0.75,(0,0,255),2)
        #cv2.putText(img, text, position, font, fontScale, color, thickness, lineType, bottomLeftOrigin)
 
        # Display tracker type on frame
        cv2.putText(frame, tracker_type + " Tracker", (100,20), cv2.FONT_HERSHEY_SIMPLEX, 0.75, (50,170,50),2);
 
        timer=(cv2.getTickCount()-timer)/cv2.getTickFrequency()
 
        #Display X and Y Coordinate
        cv2.putText(frame,"X and Y Coordinate "+str(p1)+" and "+str(p2), (100,70), cv2.FONT_HERSHEY_SIMPLEX, 0.75, (50,170,50),2);
 
        file.write(str(timer)+" :: UpperLeft(x,y) and BottomRight(x,y) "+str(p1)+" and "+str(p2)+"\n")
     
        # Display FPS on frame
        cv2.putText(frame, "FPS : " + str(int(fps)), (100,50), cv2.FONT_HERSHEY_SIMPLEX, 0.75, (50,170,50), 2);
        # Display result
        cv2.imshow("Tracking", frame)
        # Exit if ESC pressed
        k = cv2.waitKey(1) & 0xff
        if k == 27 :
            file.close()
            break

Credit : Github
Note : Code has taken from Github and modified according to need .