import cv2 as cv

 import numpy as np

 # def draw_keypoints(img, keypoints):

 #     for kp in keypoints:

 #         x, y = kp.pt

 #         cv.circle(img, (int(x), int(y)), 2, (0, 255, 0))

 # 两张键盘图片，用于特征匹配

 img1 = cv.imread('../images/keyboard1.jpg')

 img2 = cv.imread('../images/keyboard2.jpg')

 gray1 = cv.cvtColor(img1, cv.COLOR_BGR2GRAY)

 gray2 = cv.cvtColor(img2, cv.COLOR_BGR2GRAY)

 orb = cv.ORB_create()

 kp1, des1 = orb.detectAndCompute(gray1, None)  # 计算特征点和描述符

 kp2, des2 = orb.detectAndCompute(gray2, None)

 bf = cv.BFMatcher(cv.NORM_HAMMING, crossCheck=True)  # 建立匹配关系

 matches = bf.match(des1, des2)  # 匹配描述符

 matches = sorted(matches, key=lambda x:x.distance)  # 根据距离来排序

 # img3 = cv.drawMatches(gray1, kp1, gray2, kp2, matches[:10], gray2, flags=2)

 img3 = cv.drawMatches(img1, kp1, img2, kp2, matches[:10], img2, flags=2)

 cv.imshow('img3', img3)

 cv.waitKey(0)

 cv.destroyAllWindows()