Doxygen tutorials: basic structure

doc/tutorials/features2d/detection_of_planar_objects/detection_of_planar_objects.markdown

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+Detection of planar objects {#tutorial_detection_of_planar_objects}
+===========================
+
+The goal of this tutorial is to learn how to use *features2d* and *calib3d* modules for detecting
+known planar objects in scenes.
+
+*Test data*: use images in your data folder, for instance, box.png and box_in_scene.png.
+
+-   Create a new console project. Read two input images. :
+
+        Mat img1 = imread(argv[1], IMREAD_GRAYSCALE);
+        Mat img2 = imread(argv[2], IMREAD_GRAYSCALE);
+
+-   Detect keypoints in both images and compute descriptors for each of the keypoints. :
+
+        // detecting keypoints
+        Ptr<Feature2D> surf = SURF::create();
+        vector<KeyPoint> keypoints1;
+        Mat descriptors1;
+        surf->detectAndCompute(img1, Mat(), keypoints1, descriptors1);
+
+        ... // do the same for the second image
+
+-   Now, find the closest matches between descriptors from the first image to the second: :
+
+        // matching descriptors
+        BruteForceMatcher<L2<float> > matcher;
+        vector<DMatch> matches;
+        matcher.match(descriptors1, descriptors2, matches);
+
+-   Visualize the results: :
+
+        // drawing the results
+        namedWindow("matches", 1);
+        Mat img_matches;
+        drawMatches(img1, keypoints1, img2, keypoints2, matches, img_matches);
+        imshow("matches", img_matches);
+        waitKey(0);
+
+-   Find the homography transformation between two sets of points: :
+
+        vector<Point2f> points1, points2;
+        // fill the arrays with the points
+        ....
+        Mat H = findHomography(Mat(points1), Mat(points2), RANSAC, ransacReprojThreshold);
+
+-   Create a set of inlier matches and draw them. Use perspectiveTransform function to map points
+    with homography:
+
+    Mat points1Projected; perspectiveTransform(Mat(points1), points1Projected, H);
+
+-   Use drawMatches for drawing inliers.
+
+