C++ Opencv——brisk

#include<opencv2\opencv.hpp>
#include<opencv2\xfeatures2d.hpp>
using namespace cv;
using namespace xfeatures2d;
using namespace std;
 
int main(int arc, char** argv) { 
	Mat src1 = imread("1.png",IMREAD_GRAYSCALE);
	Mat src2 = imread("2.png",IMREAD_GRAYSCALE);
	namedWindow("input", CV_WINDOW_AUTOSIZE);
	imshow("input", src1);
 
	Ptr<BRISK> brisk = BRISK::create();
	vector<KeyPoint>keypoints1, keypoints2;
	Mat descriptors1, descriptors2;
	brisk->detectAndCompute(src1, Mat(), keypoints1, descriptors1);
	brisk->detectAndCompute(src2, Mat(), keypoints2, descriptors2);
	/*Mat dst1;
	drawKeypoints(src1, keypoints1, dst1);
	imshow("output1", dst1);*/
 
	BFMatcher matcher;
	vector<DMatch>matches;
	matcher.match(descriptors1, descriptors2, matches);
	Mat match_img;
	drawMatches(src1, keypoints1, src2, keypoints2, matches, match_img);
	imshow("match_img", match_img);
	
	double minDist = 1000;
	for (int i = 0; i < descriptors1.rows; i++)
	{
		double dist = matches[i].distance;
		if (dist < minDist)
		{
			minDist = dist;
		}
	}
	printf("min distance is:%f\n", minDist);
 
	vector<DMatch>goodMatches;
	for (int i = 0; i < descriptors1.rows; i++)
	{
		double dist = matches[i].distance;
		if (dist < max( 1.8*minDist, 0.02))
		{
			goodMatches.push_back(matches[i]);
		}
	}
	Mat good_match_img;
	drawMatches(src1, keypoints1, src2, keypoints2, goodMatches, good_match_img, Scalar::all(-1), Scalar::all(-1), vector<char>(), 2);
	imshow("goodMatch", good_match_img);
 
	vector<Point2f>src1GoodPoints, src2GoodPoints;
	for (int i = 0; i < goodMatches.size(); i++)
	{
		src1GoodPoints.push_back(keypoints1[goodMatches[i].queryIdx].pt);
		src2GoodPoints.push_back(keypoints2[goodMatches[i].trainIdx].pt);
	}
	Mat P = findHomography(src1GoodPoints, src2GoodPoints, RANSAC);
	vector<Point2f> src1corner(4);
	vector<Point2f> src2corner(4);
	src1corner[0] = Point(0, 0);
	src1corner[1] = Point(src1.cols, 0);
	src1corner[2] = Point(src1.cols, src1.rows);
	src1corner[3] = Point(0, src1.rows);
	perspectiveTransform(src1corner, src2corner, P);
	line(good_match_img, src2corner[0] + Point2f(src1.cols, 0), src2corner[1] + Point2f(src1.cols, 0), Scalar(0, 0, 255), 2);
	line(good_match_img, src2corner[1] + Point2f(src1.cols, 0), src2corner[2] + Point2f(src1.cols, 0), Scalar(0, 0, 255), 2);
	line(good_match_img, src2corner[2] + Point2f(src1.cols, 0), src2corner[3] + Point2f(src1.cols, 0), Scalar(0, 0, 255), 2);
	line(good_match_img, src2corner[3] + Point2f(src1.cols, 0), src2corner[0] + Point2f(src1.cols, 0), Scalar(0, 0, 255), 2);
	imshow("result", good_match_img);
	waitKey(0);
	return 0;
}