在本教程之后，尝试打开图片并与实时供稿匹配。代码已编译，没有错误，但是当我运行它时，没有打开网络摄像头/图片窗口。
我从网站上获取的代码：
import cv2
import numpy as np
img = cv2.imread("ultimo_sopravvissuto.jpg", cv2.IMREAD_GRAYSCALE) # queryiamge
cap = cv2.VideoCapture(0)
# Features
sift = cv2.xfeatures2d.SIFT_create()
kp_image, desc_image = sift.detectAndCompute(img, None)
# Feature matching
index_params = dict(algorithm=0, trees=5)
search_params = dict()
flann = cv2.FlannBasedMatcher(index_params, search_params)
_, frame = cap.read()
grayframe = cv2.cvtColor(frame, cv2.COLOR_BGR2GRAY) # trainimage
kp_grayframe, desc_grayframe = sift.detectAndCompute(grayframe, None)
matches = flann.knnMatch(desc_image, desc_grayframe, k=2)
good_points = []
for m, n in matches:
if m.distance < 0.6 * n.distance:
good_points.append(m)