ORB特征点检测和匹配

#include <stdio.h>
#include <iostream>
#include "opencv2/core/core.hpp"
#include "opencv2/features2d/features2d.hpp"
#include "opencv2/highgui/highgui.hpp"
#include <iostream>
#include <vector>
#include <QtDebug>

using namespace cv;
using namespace std;

char* image_filename2 = "F:/opencv-3.1.0/pictures/test2.bmp";
char* image_filename1 = "F:/opencv-3.1.0/pictures/test1.bmp";


int main( int argc, char** argv )
{

    Mat img_1 = imread(image_filename2);
    Mat img_2 = imread(image_filename1);
    if (!img_1.data || !img_2.data)
    {
        cout << "error reading images " << endl;
        return -1;
    }

    //ORB orb;
    Ptr<ORB> orb = ORB::create(500,1.2f,8,31,0,2,ORB::HARRIS_SCORE,31,20);
    vector<KeyPoint> keyPoints_1, keyPoints_2;
    Mat descriptors_1, descriptors_2;

#if 0
    orb->detect(img_1,keyPoints_1, Mat());
    for(int i=0;i<keyPoints_1.size();i++)
    {
        qDebug("keypoint[%d] x:%f y:%f size:%d angle:%f\n", i, keyPoints_1[i].pt.x, keyPoints_1[i].pt.y, keyPoints_1[i].size, keyPoints_1[i].angle);
    }
#endif

    orb->detectAndCompute(img_1, Mat(), keyPoints_1, descriptors_1);
    orb->detectAndCompute(img_2, Mat(), keyPoints_2, descriptors_2);

    qDebug("keyPoints1 size:%d\n", keyPoints_1.size());
    qDebug("keyPoints2 size:%d\n", keyPoints_2.size());

    flann::Index flannIndex(descriptors_2,flann::LshIndexParams(20,10,2),cvflann::FLANN_DIST_HAMMING);

    Mat matchIndex(descriptors_1.rows,2,CV_32SC1),
                matchDistance(descriptors_1.rows,2,CV_32FC1);

    flannIndex.knnSearch(descriptors_1,matchIndex,matchDistance,2,flann::SearchParams());

    int goodMatchsNum=0;
    std::vector< DMatch > good_matches;
    for(int i=0;i<matchDistance.rows;i++)
    {
       if (matchDistance.at<float>(i,0)<0.6*matchDistance.at<float>(i,1))
       {
           DMatch dmatches(i,matchIndex.at<int>(i,0),
               matchDistance.at<float>(i,0));
           good_matches.push_back( dmatches);
           goodMatchsNum++;

       }
    }
    cout<<goodMatchsNum<<endl;

    //-- Draw only "good" matches
    Mat img_matches;
    drawMatches( img_1, keyPoints_1, img_2, keyPoints_2,
               good_matches, img_matches, Scalar::all(-1), Scalar::all(-1),
               vector<char>(), DrawMatchesFlags::NOT_DRAW_SINGLE_POINTS );

    //-- Show detected matches
    imshow( "Good Matches", img_matches );

    for( int i = 0; i < good_matches.size(); i++ )
    { qDebug( "-- Good Match [%d] Keypoint 1: %d  -- Keypoint 2: %d  \n", i, good_matches[i].queryIdx, good_matches[i].trainIdx ); }

    waitKey(0);

    return 0;
 }