(Opencv Study) Orb gpu feature extraction and Matching (ORB_GPU, BruteForceMatcher_GPU example source code)

This is example source cod of ORB_GPU feature detection and matching.
ORB feature is known extraction speed is faster than surf and sift.
By the way, in my test case, speed time is not so fast.
But surf and sift is nofree algorithm. orb is free to use in commercial project.

This figure is matching result of orb example.
Note, this is gpu version result.

 

The example source code is here.
Especially, ORB is using Hamming matching method. L1 and L2 cann't use.

#include < stdio.h>
#include < iostream>

#include < opencv2\opencv.hpp>
#include < opencv2/core/core.hpp>
#include < opencv2/highgui/highgui.hpp>
//#include < opencv2/video/background_segm.hpp>
#include < opencv2\gpu\gpu.hpp>
#include < opencv2\stitching\detail\matchers.hpp >  
//#include < opencv2\nonfree\features2d.hpp >    


#ifdef _DEBUG        
#pragma comment(lib, "opencv_core247d.lib")
#pragma comment(lib, "opencv_gpu247d.lib")
#pragma comment(lib, "opencv_features2d247d.lib")
#pragma comment(lib, "opencv_highgui247d.lib")
#pragma comment(lib, "opencv_nonfree247d.lib")
#else
#pragma comment(lib, "opencv_core247.lib")
#pragma comment(lib, "opencv_gpu247.lib")
#pragma comment(lib, "opencv_features2d247.lib")
#pragma comment(lib, "opencv_highgui247.lib")
#pragma comment(lib, "opencv_nonfree247.lib");
#endif 



using namespace cv;
using namespace std;



void main()
{

 

 gpu::GpuMat img1(imread("C:\\videoSample\\Image\\Picture6.jpg", CV_LOAD_IMAGE_GRAYSCALE)); 
    gpu::GpuMat img2(imread("C:\\videoSample\\Image\\Picture7.jpg", CV_LOAD_IMAGE_GRAYSCALE)); 


 unsigned long t_AAtime=0, t_BBtime=0;
 float t_pt;
 float t_fpt;
 t_AAtime = getTickCount(); 


 
 //extractFeatures
 gpu::ORB_GPU orb(2000);
 gpu::GpuMat keypoints1GPU, keypoints2GPU; 
    gpu::GpuMat descriptors1GPU, descriptors2GPU; 

 
 orb(img1, gpu::GpuMat(), keypoints1GPU, descriptors1GPU);
 orb(img2, gpu::GpuMat(), keypoints2GPU, descriptors2GPU);

 cout << "FOUND " << keypoints1GPU.cols << " keypoints on first image" << endl; 
    cout << "FOUND " << keypoints2GPU.cols << " keypoints on second image" << endl; 

 gpu::BruteForceMatcher_GPU< Hamming > matcher;    
 vector< vector< DMatch> > matches; 
 matcher.knnMatch(descriptors1GPU, descriptors2GPU, matches, 2); 
 
 //matching
 std::vector< DMatch > good_matches;
 for(int k = 0; k < min(descriptors1GPU.rows-1,(int) matches.size()); k++) 
    {
        if((matches[k][0].distance < 0.6*(matches[k][1].distance)) && ((int) matches[k].size()<=2 && (int) matches[k].size()>0))
        {
            good_matches.push_back(matches[k][0]);
        }
    }    


 t_BBtime = getTickCount();
 t_pt = (t_BBtime - t_AAtime)/getTickFrequency();
 t_fpt = 1/t_pt;
 printf("%.4lf sec/ %.4lf fps\n",  t_pt, t_fpt );


 vector< KeyPoint> keypoints1, keypoints2;
    vector< float> descriptors1, descriptors2;
    orb.downloadKeyPoints(keypoints1GPU, keypoints1);
    orb.downloadKeyPoints(keypoints2GPU, keypoints2);
 printf("%d %d\n", keypoints1.size(), keypoints2.size() );

 
 Mat img_matches; 
 Mat img11, img22;
 img1.download(img11);
 img2.download(img22);
 Mat outImg;

    drawMatches(img11, keypoints1, img22, keypoints2, good_matches, img_matches);
 //drawKeypoints(img11, kp1, outImg);

 namedWindow("matches", 0);
    imshow("matches", img_matches);

    waitKey(0);
}

//
refer to this posting
optical flow and matching using gpu
http://feelmare.blogspot.kr/2014/07/opencv-study-opticalflow-gpu-feature.html
orb feature and matching using gpu
http://feelmare.blogspot.kr/2014/07/opencv-study-orb-gpu-feature-extraction.html
surf feature and matching using gpu
http://feelmare.blogspot.kr/2014/07/opencv-study-surf-gpu-and-matching.html