程式碼如下：

#匯入cv模組
import cv2 as cv
import numpy as np

#開操作,刪除小的干擾快
def open_demo(image):
    print(image.shape)
    gray = cv.cvtColor(image, cv.COLOR_BGR2GRAY)
    # ret, binary = cv.threshold(gray, 0, 255, cv.THRESH_BINARY | cv.THRESH_OTSU)
    ret, binary = cv.threshold(gray, 0, 255, cv.THRESH_BINARY_INV | cv.THRESH_OTSU)
    cv.imshow("binary image", binary)
    # kernel=cv.getStructuringElement(cv.MORPH_RECT,(15,1))#提取水平線
    # kernel = cv.getStructuringElement(cv.MORPH_RECT, (1, 15))  # 提取豎著的線
    kernel = cv.getStructuringElement(cv.MORPH_RECT, (4, 4))  # 提取豎著的線
    binary=cv.morphologyEx(binary,cv.MORPH_OPEN,kernel)
    cv.imshow("open-result",binary)

#閉操作
def close_demo(image):
    print(image.shape)
    gray = cv.cvtColor(image, cv.COLOR_BGR2GRAY)
    ret, binary = cv.threshold(gray, 0, 255, cv.THRESH_BINARY | cv.THRESH_OTSU)


    cv.imshow("binary image", binary)
    kernel=cv.getStructuringElement(cv.MORPH_RECT,(15,15))
    binary=cv.morphologyEx(binary,cv.MORPH_CLOSE,kernel)
    cv.imshow("close-result",binary)

print("------------Python Opencv Tutorial!-------------")
# 讀取影象，支援 bmp、jpg、png、tiff 等常用格式
#src = cv.imread("F:/Projects/images/bin2.png")
# src = cv.imread("F:/Projects/images/bin1.png")
src = cv.imread("F:/Projects/images/chars.png")
#建立視窗並顯示影象
cv.namedWindow("input image",cv.WINDOW_AUTOSIZE)
cv.imshow("input image",src)   #顯示原圖
open_demo(src)
close_demo(src)
cv.waitKey(0)
#釋放視窗
cv.destroyAllWindows()
 

執行效果：

參考連結：https://blog.csdn.net/water_93/article/details/50859193

 形態學的其他操作：https://blog.csdn.net/qq_30490125/article/details/80490776

程式碼示例：

#匯入cv模組
import cv2 as cv
import numpy as np
#頂帽 黑帽 基於灰度影象的
def top_hat_demo(image):
    gray=cv.cvtColor(image,cv.COLOR_BGR2GRAY)
    kernel=cv.getStructuringElement(cv.MORPH_RECT,(15,15))
    # dst=cv.morphologyEx(gray,cv.MORPH_TOPHAT,kernel)#頂帽
    dst = cv.morphologyEx(gray, cv.MORPH_BLACKHAT, kernel)  # 頂
    cimage=np.array(gray.shape,np.uint8)#黑帽
    cimage=100
    dst=cv.add(dst,cimage)
    cv.imshow("tophat",dst)

#頂帽 黑帽 基於二值影象的
def top_binary_demo(image):
    gray=cv.cvtColor(image,cv.COLOR_BGR2GRAY)
    ret,binary=cv.threshold(gray,0,255,cv.THRESH_BINARY|cv.THRESH_OTSU)
    kernel=cv.getStructuringElement(cv.MORPH_RECT,(15,15))
    # dst = cv.morphologyEx(binary, cv.MORPH_TOPHAT, kernel) #頂帽
    dst = cv.morphologyEx(binary, cv.MORPH_BLACKHAT, kernel)  # 黑帽

    cv.imshow("tophat",dst)

#梯度 基於二值影象的
def gradient_demo(image):
    gray=cv.cvtColor(image,cv.COLOR_BGR2GRAY)
    ret,binary=cv.threshold(gray,0,255,cv.THRESH_BINARY|cv.THRESH_OTSU)
    kernel=cv.getStructuringElement(cv.MORPH_RECT,(3,3))
    # dst = cv.morphologyEx(binary, cv.MORPH_TOPHAT, kernel) #頂帽
    dst = cv.morphologyEx(binary, cv.MORPH_GRADIENT, kernel)  #梯度
    cv.imshow("gradient_demo",dst)

def gradient2_demo(image):
    kernel=cv.getStructuringElement(cv.MORPH_RECT,(3,3))
    dm=cv.dilate(image,kernel)
    em=cv.dilate(image,kernel)
    dst1=cv.subtract(image,em)#inrernal gradient
    dst2 = cv.subtract(dm, image)  #external gradient
    cv.imshow("internal",dst1)
    cv.imshow("external", dst2)

print("------------Python Opencv Tutorial!-------------")
# 讀取影象，支援 bmp、jpg、png、tiff 等常用格式
src = cv.imread("F:/Projects/images/bin2.png")
#建立視窗並顯示影象
cv.namedWindow("input image",cv.WINDOW_AUTOSIZE)
cv.imshow("input image",src)   #顯示原圖
# top_hat_demo(src)
# top_binary_demo(src)
#gradient_demo(src)
gradient2_demo(src)
cv.waitKey(0)
#釋放視窗
cv.destroyAllWindows()