Tutorial: Keypoint matching (deprecated)
This tutorial shows how to detect and match SURF keypoints. It will be deprecated if you use an OpenCV version equal to 2.8.0 or a more recent version.
Tutorial: Face detection
This tutorial focuses on face detection thanks to OpenCV Haar cascade classifier.
Tutorial: Object detection and localization
This tutorial shows how to learn keypoints detected on a known object and how to use the matched correspondences to detect and estimate the pose of the object.