opencv在python下的安装和使用

安装opencv

1 2	pip3 install numpy pip3 install opencv-python

在安装opencv-python出现了以下错误信息:

Could not fetch URL https://pypi.org/simple/opencv-python/: There was a problem confirming the ssl certificate: HTTPSConnectionPool(host='pypi.org', port=443): Max retries exceeded with url: /simple/opencv-python/ (Caused by SSLError(SSLError(1, u'[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed (_ssl.c:726)'),)) - skipping

解决方案:

1	pip3 install --trusted-host pypi.org --trusted-host files.pythonhosted.org opencv-python

opencv rotate code

import sys
import cv2
import numpy as np


if len(sys.argv) != 2 :
    print("usage: ./images path")
    sys.exit(1)

img = cv2.imread(sys.argv[1])
cv2.imshow("Source", img)

img90 = np.rot90(img) # 旋转90
cv2.imshow("Rotate", img90)

cv2.waitKey(0)
cv2.destroyAllWindows()