The Corner Tracker example resides in the L3/examples/cornertracker directory.
This benchmark tests the performance of the cornertracker function with a sequence of two images. This example illustrates how to detect and track the characteristic feature points in a set of successive frames of video. A Harris corner detector is used as the feature detector, and a modified version of the Lucas Kanade optical flow is used for tracking. The core part of the algorithm takes in the current and next frame as the inputs and outputs the list of tracked corners. The current image is the first frame in the set, then corner detection is performed to detect the features to track.
The tutorial provides a step-by-step guide that covers commands for building and running a kernel.