openCv图片的读取

import cv2
# 绘图包
import matplotlib.pyplot as pyplot
#数值计算的包
import numpy as np 

#opencv读取的格式是BGR
img = cv2.imread("./xing.jpg")
#读取灰度图
img = cv2.imread('./xing.jpg',cv2.IMREAD_GRAYSCALE)
print(img)

#图像的显示
cv2.imshow("image",img)
#等待时间，0表示任意键终止
cv2.waitKey(0)
#销毁窗口
cv2.destroyAllWindows()

#保存
cv2.imwrite("./xing.jpg",img)