import numpy as np

import cv2



def fillholse(im_th):

    '''

    空洞填充

    param:

        im_th:二值图像

    return:

        im_out:填充好的图像

    '''

    # Copy the thresholded image.

    im_floodfill = im_th.copy()



    # Mask used to flood filling.

    # Notice the size needs to be 2 pixels than the image.

    h, w = im_th.shape[:2]

    mask = np.zeros((h + 2, w + 2), np.uint8)



    # Floodfill from point (0, 0)

    retval, image, mask, rect = cv2.floodFill(im_floodfill, mask, (0, 0), 255)



    # Invert floodfilled image

    im_floodfill_inv = cv2.bitwise_not(im_floodfill)



    # Combine the two images to get the foreground.

    im_out = im_th | im_floodfill_inv

    return im_out