Use the opencv functions surffeaturedetector and detect to detect interest points;
Use the opencv function drawkeypoints to draw the detection key points.
/** * @file SURF_detector * @brief SURF keypoint detection + keypoint drawing with OpenCV functions * @author A. Huaman */#include <stdio.h>#include <iostream>#include "opencv2/core/core.hpp"#include "opencv2/features2d/features2d.hpp"#include "opencv2/highgui/highgui.hpp"#include "opencv2/nonfree/features2d.hpp"using namespace cv;void readme();/** * @function main * @brief Main function */int main( int argc, char** argv ){ if( argc != 3 ) { readme(); return -1; } Mat img_1 = imread( argv[1], CV_LOAD_IMAGE_GRAYSCALE ); Mat img_2 = imread( argv[2], CV_LOAD_IMAGE_GRAYSCALE ); if( !img_1.data || !img_2.data ) { std::cout<< " --(!) Error reading images " << std::endl; return -1; } //-- Step 1: Detect the keypoints using SURF Detector int minHessian = 400; SurfFeatureDetector detector( minHessian ); std::vector<KeyPoint> keypoints_1, keypoints_2; detector.detect( img_1, keypoints_1 ); detector.detect( img_2, keypoints_2 ); //-- Draw keypoints Mat img_keypoints_1; Mat img_keypoints_2; drawKeypoints( img_1, keypoints_1, img_keypoints_1, Scalar::all(-1), DrawMatchesFlags::DEFAULT ); drawKeypoints( img_2, keypoints_2, img_keypoints_2, Scalar::all(-1), DrawMatchesFlags::DEFAULT ); //-- Show detected (drawn) keypoints imshow("Keypoints 1", img_keypoints_1 ); imshow("Keypoints 2", img_keypoints_2 ); waitKey(0); return 0;}/** * @function readme */void readme(){ std::cout << " Usage: ./SURF_detector