import numpy as np
import cv2
from matplotlib import pyplot as plt

img=cv2.imread('trial.jpg')
gray=cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)
ret,tresh=cv2.threshold(gray,0,255,cv2.THRESH_BINARY_INV+cv2.THRESH_OTSU)
kernel=np.ones((3,3),np.uint8)
opening=cv2.morphologyEx(tresh,cv2.MORPH_OPEN,kernel, iterations=2)

sure_bg=cv2.dilate(opening,kernel,iterations=3)
dist_transform=cv2.distanceTransform(opening,cv2.DIST_L2,5)
ret,sure_fg=cv2.threshold(dist_transform,0.7*dist_transform.max(),255,0)
sure_fg=np.uint8(sure_fg)
unknown=cv2.subtract(sure_bg,sure_fg)
ret,markers=cv2.connectedComponents(sure_fg)
markers=markers+1
markers[unknown==255]=0
markers=cv2.watershed(img,markers)
img[markers==-1]=[255,0,0]
cv2.imshow('markers',markers)
cv2.waitKey(0)

