01 sift 找出特徵點

    #include <stdio.h>
    #include <iostream>
    #include <opencv2/core/core.hpp>
    #include <opencv2/features2d/features2d.hpp>
    #include <opencv2/nonfree/features2d.hpp>
    #include <opencv2/highgui/highgui.hpp>
    #include <opencv2/nonfree/nonfree.hpp>
    
    using namespace cv;
    
    void readme();
    
    /** @function main */
    int main( int argc, char** argv )
    {
        //if( argc != 3 )
        //{ readme(); return -1; }
        
        Mat img_1 = imread( "/Users/powenko/Desktop/taipei_101_2.jpg", CV_LOAD_IMAGE_GRAYSCALE );
        Mat img_2 = imread( "/Users/powenko/Desktop/taipei_101.jpg", 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;
        
         SiftFeatureDetector detector;
        
        
        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 <img1> <img2>" << std::endl; }
    
    
    
    

    screen-shot-2016-12-02-at-7-34-41-pm