輸入：img(二值圖)
輸出：out(和img一樣shape的圖像，初始化是全0)
while img中有像素值為255(在這個(gè)循環(huán)里面，一直腐蝕我們的二值圖，直到全部為黑色):
    腐蝕img圖像
    對(duì)img開運(yùn)算
	img2=開運(yùn)算前的圖像減去開運(yùn)算后的圖像
	out+=img2
輸出out

'''
用于挑選一個(gè)好的二值圖
'''
import cv2
import numpy as np
import os

def refine(img_path):
    img = cv2.imread(img_path, cv2.IMREAD_GRAYSCALE)
    # thresh, img = cv2.threshold(img, 0, 255, cv2.THRESH_BINARY + cv2.THRESH_OTSU)
    thresh, img = cv2.threshold(img, 50, 255, cv2.THRESH_BINARY)
    h, w = img.shape[0:2]
    #前景背景反轉(zhuǎn)
    for i in range(h):
        for j in range(w):
            if img[i, j] == 255:
                img[i, j] = 0
            else:
                img[i, j] = 255
    cv2.namedWindow("binary", 0)
    cv2.resizeWindow("binary", 640, 480)
    cv2.imshow('binary', img)
    dst = img.copy()

    num_erode = 0

    while (True):
        if np.sum(dst) == 0:
            break
        kernel = cv2.getStructuringElement(cv2.MORPH_CROSS, (3, 3))
        dst = cv2.erode(dst, kernel)
        cv2.namedWindow("z", 0)
        cv2.resizeWindow("z", 640, 480)
        cv2.imshow('z', dst)
        c = cv2.waitKey(0)
        if c == ord("q"):
            print("保存")
            cv2.imwrite("./refine.png", dst)
            break
        num_erode = num_erode + 1

if __name__ == '__main__':
    refine("input.png")

'''
骨架提取
'''
import cv2
import numpy as np

#由于我們經(jīng)過之前的代碼轉(zhuǎn)換到了二值圖，所以這里不需要轉(zhuǎn)換
img = cv2.imread('refine.png', cv2.IMREAD_GRAYSCALE)
dst = img.copy()

skeleton = np.zeros(dst.shape, np.uint8)
while (True):
    if np.sum(dst) == 0:
        break
    kernel = cv2.getStructuringElement(cv2.MORPH_CROSS, (7, 7))
    dst = cv2.erode(dst, kernel, None, None, 1)
    open_dst = cv2.morphologyEx(dst, cv2.MORPH_OPEN, kernel)
    result = dst - open_dst
    skeleton = skeleton + result
    cv2.waitKey(1)



cv2.namedWindow("result",0)
cv2.resizeWindow("result",640,480)
cv2.imshow('result', skeleton)
cv2.imwrite("output.png",skeleton)

cv2.waitKey(0)
cv2.destroyAllWindows()