在下面的程序中：

#include "opencv2/core/core.hpp"
#include "opencv2/features2d/features2d.hpp"
#include "opencv2/highgui/highgui.hpp"
#include <opencv2/nonfree/nonfree.hpp>
#include<opencv2/legacy/legacy.hpp>
using namespace cv;


int main( int argc, char** argv )
{
	Mat img_1 = imread( "F:\\VS2010\\OpenCVPro\\OpenCVTest\\Pic\\6.jpg",CV_LOAD_IMAGE_GRAYSCALE );
	Mat img_2 = imread( "F:\\VS2010\\OpenCVPro\\OpenCVTest\\Pic\\7.jpg", CV_LOAD_IMAGE_GRAYSCALE );

	if( !img_1.data || !img_2.data )
	{ return -1; }

	//-- Step 1: Detect the keypoints using SURF Detector
	int minHessian = 400;
	SurfFeatureDetector detector( minHessian );
	std::vector<KeyPoint> keypoints_1, keypoints_2;
	detector.detect( img_1, keypoints_1 );
	detector.detect( img_2, keypoints_2 );

	//-- Step 2: Calculate descriptors (feature vectors)
	SurfDescriptorExtractor extractor;
	Mat descriptors_1, descriptors_2;
	extractor.compute( img_1, keypoints_1, descriptors_1 );
	extractor.compute( img_2, keypoints_2, descriptors_2 );

	//-- Step 3: Matching descriptor vectors with a brute force matcher
	BruteForceMatcher< L2<float> > matcher;
	std::vector< DMatch > matches;
	matcher.match( descriptors_1, descriptors_2, matches );

	//-- Draw matches
	Mat img_matches;
	drawMatches( img_1, keypoints_1, img_2, keypoints_2, matches, img_matches );
	//-- Show detected matches
	imshow("Matches", img_matches );
	waitKey(0);
	return 0;
}