python 2.7 - matching error in ORB with opencv 3 -

currently working on opevcv python when use

    kp1 = orb.detect(img1,none)     kp2 = orb.detect(img2,none)     kp1, des1 = orb.compute(img1, kp1)     kp2, des2 = orb.compute(img2, kp2)     matches = matcher.match(des1, des2) 

i error matcher not defined

    matches = matcher.match(des1, des2)     nameerror: name 'matcher' not defined 

, using opencv 3.0.0 python 2.7, can tell me why getting error ?? can use matcher or not python ??

you need create matcher object first. complete example can found on opencv tutorials:

import numpy np import cv2 matplotlib import pyplot plt  img1 = cv2.imread('box.png',0)          # queryimage img2 = cv2.imread('box_in_scene.png',0) # trainimage  # initiate orb detector orb = cv2.orb()  # find keypoints , descriptors orb kp1, des1 = orb.detectandcompute(img1,none) kp2, des2 = orb.detectandcompute(img2,none)  # create bfmatcher object bf = cv2.bfmatcher(cv2.norm_hamming, crosscheck=true)  # match descriptors. matches = bf.match(des1,des2)  # sort them in order of distance. matches = sorted(matches, key = lambda x:x.distance)  # draw first 10 matches. img3 = cv2.drawmatches(img1,kp1,img2,kp2,matches[:10], flags=2)  plt.imshow(img3),plt.show()