#include <iostream>
#include <vector>
#include "opencv2/core.hpp"
#ifdef HAVE_OPENCV_XFEATURES2D
#include "opencv2/highgui.hpp"
#include "opencv2/features2d.hpp"
#include "opencv2/xfeatures2d.hpp"
#include <opencv2/highgui/highgui.hpp>
#include <opencv2/imgproc/imgproc.hpp>
#include <opencv/cv.hpp>
#include <opencv2/imgcodecs/imgcodecs.hpp>
#include <opencv2/calib3d/calib3d.hpp>
#include <opencv2/features2d/features2d.hpp>
#include <opencv2/features2d.hpp>
#include <opencv2/calib3d.hpp>
using namespace cv;
using namespace cv::xfeatures2d;
using std::cout;
using std::endl;
int main( int argc, char* argv[] )
{
    CommandLineParser parser( argc, argv, "{@input | box.png | input image}" );
    Mat img1 = imread(argv[1], IMREAD_GRAYSCALE );
    Mat img2 = imread(argv[2], IMREAD_GRAYSCALE );
    if ( img1.empty() )
    {
        cout << "Could not open or find the image!\n" << endl;
        cout << "Usage: " << argv[0] << " <Input image>" << endl;
        return -1;
    }
    Mat wide = imread("image_wide.png", IMREAD_GRAYSCALE );
    //-- Step 1: Detect the keypoints using SURF Detector
    int minHessian = 400;
    Ptr<SURF> detector = SURF::create( minHessian );
    std::vector<KeyPoint> keypoints1;
    std::vector<KeyPoint> keypoints2;
    detector->detect(img2, keypoints2);
    detector->detect(img1, keypoints1);

    Ptr<SURF> extractor = SURF::create();
    Mat descriptors1, descriptors2;
    extractor->compute(img1, keypoints1, descriptors1);
    extractor->compute(img2, keypoints2, descriptors2);

    //BFMatcher<L2<float> > matcher;
    DescriptorMatcher* matcher = new BFMatcher(NORM_L2,false);
    std::vector<DMatch> matches;
    matcher->match(descriptors1, descriptors2, matches);

    namedWindow("matches", 1);
    Mat img_matches;
    drawMatches(img1, keypoints1, img2, keypoints2, matches, img_matches);
    imshow("matches", img_matches);
    waitKey(0);

    //-- Draw keypoints
    Mat img_keypoints;
    drawKeypoints(img1, keypoints1, img_keypoints );
    //-- Show detected (drawn) keypoints
    imshow("SURF Keypoints", img_keypoints );
    waitKey();
    return 0;
}
#else
int main()
{
    std::cout << "This tutorial code needs the xfeatures2d contrib module to be run." << std::endl;
    return 0;
}
#endif