|  | OpenCV
    3.4.9
    Open Source Computer Vision | 
| Classes | |
| class | cv::xfeatures2d::SIFT | 
| Class for extracting keypoints and computing descriptors using the Scale Invariant Feature Transform (SIFT) algorithm by D. Lowe [132] .  More... | |
| class | cv::xfeatures2d::SURF | 
| Class for extracting Speeded Up Robust Features from an image [12] .  More... | |
| class | cv::cuda::SURF_CUDA | 
| Class used for extracting Speeded Up Robust Features (SURF) from an image. :  More... | |
| Typedefs | |
| typedef SIFT | cv::xfeatures2d::SiftDescriptorExtractor | 
| typedef SIFT | cv::xfeatures2d::SiftFeatureDetector | 
| typedef SURF | cv::xfeatures2d::SurfDescriptorExtractor | 
| typedef SURF | cv::xfeatures2d::SurfFeatureDetector | 
This section describes two popular algorithms for 2d feature detection, SIFT and SURF, that are known to be patented. You need to set the OPENCV_ENABLE_NONFREE option in cmake to use those. Use them at your own risk.
#include <opencv2/xfeatures2d/nonfree.hpp>
#include <opencv2/xfeatures2d/nonfree.hpp>
#include <opencv2/xfeatures2d/nonfree.hpp>
#include <opencv2/xfeatures2d/nonfree.hpp>
 1.8.13
 1.8.13