Added a simple sample for descriptor matching

samples/cpp/matcher_simple.cpp

+#include <stdio.h>
+#include <opencv2/core/core.hpp>
+#include <opencv2/features2d/features2d.hpp>
+#include <opencv2/highgui/highgui.hpp>
+
+using namespace cv;
+
+int main(int argc, char** argv)
+{
+	if(argc != 3)
+	{
+		printf("Usage: matches_simple <image1> <image2>\n");
+		return -1;
+	}
+
+	Mat img1 = imread(argv[1]);
+	Mat img2 = imread(argv[2]);
+	if(img1.empty() || img2.empty())
+	{
+		printf("Can't read one of the images\n");
+		return -1;
+	}
+
+	// detecting keypoints
+	SurfFeatureDetector detector(400);
+	vector<KeyPoint> keypoints1, keypoints2;
+	detector.detect(img1, keypoints1);
+	detector.detect(img2, keypoints2);
+
+	// computing descriptors
+	SurfDescriptorExtractor extractor;
+	Mat descriptors1, descriptors2;
+	extractor.compute(img1, keypoints1, descriptors1);
+	extractor.compute(img2, keypoints2, descriptors2);
+
+	// matching descriptors
+	BruteForceMatcher<L2<float> > matcher;
+	vector<int> matches;
+	matcher.add(descriptors1);
+	matcher.match(descriptors2, matches);
+
+	// drawing the results
+	namedWindow("matches", 1);
+	Mat img_matches;
+	drawMatches(img1, img2, keypoints1, keypoints2, matches, vector<char>(), img_matches);
+	imshow("matches", img_matches);
+	waitKey(0);
+
+	return 0;
+}