Drawing a rectangle around all contours in OpenCV Python

Question

i have a code which identifies contours after applying filters on video frames. Now in my case i get 3 contours and i show them by drawing rectangles around them, what i want to

Answer 1

Using numpy:

boxes = []
for c in cnts:
    (x, y, w, h) = cv2.boundingRect(c)
    boxes.append([x,y, x+w,y+h])

boxes = np.asarray(boxes)
left, top = np.min(boxes, axis=0)[:2]
right, bottom = np.max(boxes, axis=0)[2:]

cv2.rectangle(frame, (left,top), (right,bottom), (255, 0, 0), 2)