#include <stdio.h>

#include <iostream>

#include "opencv2/core/core.hpp"

#include "opencv2/highgui/highgui.hpp"

#include<opencv2/legacy/legacy.hpp>

#include "opencv2/nonfree/features2d.hpp" //SurfFeatureDetector實際在該標頭檔案中

using namespace cv;

using namespace std;

int main(int argc, char** argv)

{

Mat src = imread("1.jpg", 1);

Mat src2 = imread("2.jpg", 1);//旋轉後

if (!src.data||!src2.data)

{

cout << " --(!) Error reading images " << endl;

}

//1--初始化SIFT檢測運算元

int minHessian = 40;

SiftFeatureDetector detector(minHessian);

//2--使用SIFT運算元檢測特徵點

vector<KeyPoint> kp1,kp2;

detector.detect(src, kp1);

detector.detect(src2, kp2);

//--繪製特徵點

Mat keypointImg, keypointImg2;

drawKeypoints(src, kp1, keypointImg, Scalar::all(-1), DrawMatchesFlags::DEFAULT);

imshow("SIFT kp1", keypointImg);

cout << "keypoint1 number: " << kp1.size() << endl;

drawKeypoints(src, kp2, keypointImg2, Scalar::all(-1), DrawMatchesFlags::DEFAULT);

imshow("SIFT kp2", keypointImg2);

cout << "keypoint2 number: " << kp2.size() << endl;

//3--特徵向量提取

SiftDescriptorExtractor extractor;

Mat descriptor1, descriptor2;

extractor.compute(src, kp1, descriptor1);

extractor.compute(src2, kp2, descriptor2);

//imshow("desc", descriptor1);

//cout << endl << descriptor1 << endl;

//4--特徵匹配

BruteForceMatcher<L2<float>> matcher;

vector<DMatch> matches;

Mat matches;

matcher.match(descriptor1, descriptor2, matches);

//--繪製匹配

drawMatches(src, kp1, src2, kp2, matches, matches);

imshow("matches", matches);

waitKey(0);

return 0;

}