import cv2
import numpy as np

获取背景

1.通过二值法得到黑白图片

2.通过形态学获取北京

img = cv2.imread(‘imgs/yb.png’)
cv2.imshow(‘img’,img)

img = cv2.imread(‘images/yn.png’)

gray = cv2.cvtColor(img,cv2.COLOR_BGR2GRAY)
cv2.imshow(‘gray’,gray)

ret,thresh = cv2.threshold(gray,0,255,cv2.THRESH_BINARY_INV+cv2.THRESH_OTSU)
cv2.imshow(‘thresh’,thresh)
#开运算 去除噪点
kernel = np.ones((3,3),np.int8)
open1 = cv2.morphologyEx(thresh,cv2.MORPH_OPEN,kernel,iterations=2)
cv2.imshow(‘open1’,open1)

膨胀

bg = cv2.dilate(open1,kernel,iterations=1)

cv2.imshow(‘bg’,bg)
cv2.waitKey(0)