import cv2
import numpy as np

file_name = 'area1.png'
img = cv2.imread(file_name)
kernel = np.ones((5,5), np.uint8)
opening = img
i = 0
while i < 1:
    opening = cv2.morphologyEx(opening, cv2.MORPH_CLOSE, kernel)
    opening = cv2.morphologyEx(opening, cv2.MORPH_OPEN, kernel)
    i = i + 1
kernel = np.ones((1,1), np.uint8)
#opening = cv2.erode(opening, kernel, iterations = 1)

cv2.imwrite('marea.png', opening)