import imutils
import cv2

img = cv2.imread('a.jpg')
img = cv2.cvtColor(img, cv2.COLOR_BGR2GRAY)
# threshold image
ret, threshed_img = cv2.threshold(blurred, 200, 255, cv2.THRESH_BINARY_INV)
# find contours and get the external one

#edged = imutils.auto_canny(threshed_img)

ctrz = cv2.findContours(threshed_img, cv2.RETR_EXTERNAL,cv2.CHAIN_APPROX_SIMPLE)
cnts = imutils.grab_contours(ctrz)
(cnts, boundingBoxes) = contours.sort_contours(cnts, method="left-to-right")
boundingBoxes = list(boundingBoxes)