Boundingbox defintion for opencv object tracking

Question

How is the boundingbox object defined that takes opencv's tracker.init() function? is it (xcenter,ycenter,boxwidht,boxheight) or (xmin,ymin,xmax,ymax) or (ymin,xmin,ymax,xmax) or something completely different?

I am using python and OpenCV 3.3 and i basically do the following on each object i want to track for each frame of a video:

tracker = cv2.trackerKCF_create()
ok = tracker.init(previous_frame,bbox)
bbox = tracker.update(current_frame)

Answer 1

The Answer is: (xmin,ymin,boxwidth,boxheight)