python opencv FLANN

FLANN是OpenCV中的一个模块，用于快速最近邻搜索。它可以用于图像匹配、聚类和其他机器学习应用。下面是一个使用FLANN进行图像匹配的Python示例代码：

import cv2
import numpy as np

img1 = cv2.imread('img1.jpg', 0)
img2 = cv2.imread('img2.jpg', 0)

# 初始化SIFT检测器
sift = cv2.xfeatures2d.SIFT_create()

# 检测关键点和描述符
kp1, des1 = sift.detectAndCompute(img1, None)
kp2, des2 = sift.detectAndCompute(img2, None)

# FLANN参数
FLANN_INDEX_KDTREE = 1
index_params = dict(algorithm=FLANN_INDEX_KDTREE, trees=5)
search_params = dict(checks=50)

# 创建FLANN匹配器
flann = cv2.FlannBasedMatcher(index_params, search_params)

# 匹配描述符
matches = flann.knnMatch(des1, des2, k=2)

# 根据Lowe's比率测试保留好的匹配
good_matches = []
for m, n in matches:
    if m.distance < 0.7 * n.distance:
        good_matches.append(m)

# 绘制匹配结果
img3 = cv2.drawMatches(img1, kp1, img2, kp2, good_matches, None, flags=2)

cv2.imshow('Matches', img3)
cv2.waitKey(0)
cv2.destroyAllWindows()