Fill in areas that are not closed areas

notclosed_floodfill.py

import sys
import numpy as np
import cv2

def dilate(src, ksize=3):
    h, w = src.shape
    dst = src.copy()
    d = int((ksize-1)/2)

    for y in range(0, h):
        for x in range(0, w):
            roi = src[y-d:y+d+1, x-d:x+d+1]
            if np.count_nonzero(roi) > 0:
                dst[y][x] = 255

    return dst

def erode(src, ksize=3):
    h, w = src.shape
    dst = src.copy()
    d = int((ksize-1)/2)

    for y in range(0, h):
        for x in range(0, w):
            roi = src[y-d:y+d+1, x-d:x+d+1]
            if roi.size - np.count_nonzero(roi) > 0:
                dst[y][x] = 0

    return dst

_, infile, outfile = sys.argv

img = cv2.imread(infile)

#decolor
img_gray, _ = cv2.decolor(img);

#thresh/inverse
ret,thresh = cv2.threshold(img_gray,127,255,cv2.THRESH_BINARY_INV)

#Dilation
dilate_img = dilate(thresh, ksize=20)

#Erosion
erode_img = erode(dilate_img, ksize=16)

#inverse
img1 = cv2.bitwise_not(erode_img)

#findCountours
contours,hierarchy =  cv2.findContours(img1,cv2.RETR_TREE,cv2.CHAIN_APPROX_SIMPLE)
cnt = contours[0]

#Find the coordinates of both ends.
h, w = img1.shape

leftmin = w 
leftup = h 
for i in cnt:
    (x,y)=i[0]
    if 0 < x < leftmin:
        leftmin = x
        if 0 < y < leftup:
            leftup = y

rightmax = 0
rightup = h
for i in cnt:
    (x,y)=i[0]
    if w - 1 > x > rightmax:
        rightmax = x
        if 0 < y < rightup:
            rightup = y
#draw line
img1 = cv2.line(img1,(leftmin,leftup),(rightmax,rightup),(0,0,255),2)
cv2.imwrite(outfile, img1)
img1 = cv2.imread(outfile)

#Points are left on purpose !
img1 = cv2.drawContours(img1, cnt, -1, (255,0,0), 2)

#paint out 
mask = cv2.Canny(img1, 100, 200) 
mask = cv2.copyMakeBorder(mask, 1, 1, 1, 1, cv2.BORDER_REPLICATE)
cv2.floodFill( img1, mask, (120,120), (0,255,255))
sz = img1.shape[:2]
cv2.floodFill( img1, mask, (int(sz[0]/2), int(sz[1]/2)), (0,255,0))

cv2.imwrite(outfile, img1)