Oriented FAST and Rotated BRIEF (ORB)

So, now we have arrived at the best combination out of all the combinations that we have discussed so far. This algorithm came out of the OpenCV Labs. It's fast, robust, and open-source! Both SIFT and SURF algorithms are patented and you can't use them for commercial purposes. This is why ORB is good in many ways.

If you run the ORB keypoint extractor on one of the images shown earlier, you will see something like the following:

Here is the code:

import cv2
import numpy as np

input_image = cv2.imread('input.jpg')
gray_image = cv2.cvtColor(input_image, cv2.COLOR_BGR2GRAY)

# Initiate ORB object
orb = cv2.ORB()

# find the keypoints with ORB
keypoints = orb.detect(gray_image, None)

# compute the descriptors with ORB
keypoints, descriptors = orb.compute(gray_image, keypoints)

# draw only the location of the keypoints without size or orientation
final_keypoints = cv2.drawKeypoints(input_image, keypoints, color=(0,255,0), flags=0)

cv2.imshow('ORB keypoints...