Detecting Fast Hessian features and extracting SURF descriptors
Computer vision is a relatively young branch of computer science, so many famous algorithms and techniques have only been invented recently. SIFT is, in fact, only 23 years old, having been published by David Lowe in 1999.
SURF is a feature detection algorithm that was published in 2006 by Herbert Bay. SURF is several times faster than SIFT, and it is partially inspired by it.
Note that SURF is a patented algorithm and, for this reason, is made available only in builds of
opencv_contribwhere theOPENCV_ENABLE_NONFREECMake flag is used. SIFT was formerly a patented algorithm but its patent expired and now SIFT is available in standard builds of OpenCV.
It is not particularly relevant to this book to understand how SURF works under the hood, inasmuch as we can use it in our applications and make the best of it. What is important to understand is that cv2.SURF is an OpenCV class that performs keypoint detection with the...
