October 2015
Intermediate to advanced
230 pages
5h 10m
English
This chapter showed a robust feature tracking method that is fast enough to run in real time when applied to the live stream of a webcam.
First, the algorithm shows you how to extract and detect important features in an image independently of perspective and size, be it in a template of our object of interest (train image) or a more complex scene in which we expect the object of interest to be embedded (query image). A match between feature points in the two images is then found by clustering the keypoints using a fast version of the nearest neighbor algorithm. From there on, it is possible to calculate a perspective transformation that maps one set of feature points to the other. With this information, we can outline the train image as ...