diff --git a/doc/conf.py b/doc/conf.py index 621987608..7d1ed1f39 100644 --- a/doc/conf.py +++ b/doc/conf.py @@ -368,7 +368,10 @@ extlinks = {'cvt_color': ('http://opencv.willowgarage.com/documentation/cpp/imgp 'surf_descriptor_extractor' : ( 'http://opencv.willowgarage.com/documentation/cpp/features2d_common_interfaces_of_descriptor_extractors.html#surfdescriptorextractor%s', None ), 'draw_matches' : ( 'http://opencv.willowgarage.com/documentation/cpp/features2d_drawing_function_of_keypoints_and_matches.html#cv-drawmatches%s', None ), 'find_homography' : ('http://opencv.willowgarage.com/documentation/cpp/calib3d_camera_calibration_and_3d_reconstruction.html?#findHomography%s', None), - 'perspective_transform' : ('http://opencv.willowgarage.com/documentation/cpp/core_operations_on_arrays.html?#perspectiveTransform%s', None ) + 'perspective_transform' : ('http://opencv.willowgarage.com/documentation/cpp/core_operations_on_arrays.html?#perspectiveTransform%s', None ), + 'flann_based_matcher' : ('http://opencv.willowgarage.com/documentation/cpp/features2d_common_interfaces_of_descriptor_matchers.html?#FlannBasedMatcher%s', None), + 'brute_force_matcher' : ('http://opencv.willowgarage.com/documentation/cpp/features2d_common_interfaces_of_descriptor_matchers.html?#BruteForceMatcher%s', None ), + 'flann' : ('http://opencv.willowgarage.com/documentation/cpp/flann_fast_approximate_nearest_neighbor_search.html?%s', None ) } diff --git a/doc/tutorials/features2d/feature_description/feature_description.rst b/doc/tutorials/features2d/feature_description/feature_description.rst index a1a25fc9e..ee139355a 100644 --- a/doc/tutorials/features2d/feature_description/feature_description.rst +++ b/doc/tutorials/features2d/feature_description/feature_description.rst @@ -13,6 +13,7 @@ In this tutorial you will learn how to: * Use the :descriptor_extractor:`DescriptorExtractor<>` interface in order to find the feature vector correspondent to the keypoints. Specifically: * Use :surf_descriptor_extractor:`SurfDescriptorExtractor<>` and its function :descriptor_extractor:`compute<>` to perform the required calculations. + * Use a :brute_force_matcher:`BruteForceMatcher<>` to match the features vector * Use the function :draw_matches:`drawMatches<>` to draw the detected matches. diff --git a/doc/tutorials/features2d/feature_flann_matcher/feature_flann_matcher.rst b/doc/tutorials/features2d/feature_flann_matcher/feature_flann_matcher.rst new file mode 100644 index 000000000..10135ff67 --- /dev/null +++ b/doc/tutorials/features2d/feature_flann_matcher/feature_flann_matcher.rst @@ -0,0 +1,132 @@ +.. _feature_flann_matcher: + +Feature Matching with FLANN +**************************** + +Goal +===== + +In this tutorial you will learn how to: + +.. container:: enumeratevisibleitemswithsquare + + * Use the :flann_based_matcher:`FlannBasedMatcher<>` interface in order to perform a quick and efficient matching by using the :flann:`FLANN<>` ( *Fast Approximate Nearest Neighbor Search Library* ) + + +Theory +====== + +Code +==== + +This tutorial code's is shown lines below. You can also download it from `here `_ + +.. code-block:: cpp + + #include + #include + #include "opencv2/core/core.hpp" + #include "opencv2/features2d/features2d.hpp" + #include "opencv2/highgui/highgui.hpp" + + using namespace cv; + + void readme(); + + /** @function main */ + int main( int argc, char** argv ) + { + if( argc != 3 ) + { readme(); return -1; } + + Mat img_1 = imread( argv[1], CV_LOAD_IMAGE_GRAYSCALE ); + Mat img_2 = imread( argv[2], CV_LOAD_IMAGE_GRAYSCALE ); + + if( !img_1.data || !img_2.data ) + { std::cout<< " --(!) Error reading images " << std::endl; return -1; } + + //-- Step 1: Detect the keypoints using SURF Detector + int minHessian = 400; + + SurfFeatureDetector detector( minHessian ); + + std::vector 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 using FLANN matcher + FlannBasedMatcher matcher; + std::vector< DMatch > matches; + matcher.match( descriptors_1, descriptors_2, matches ); + + double max_dist = 0; double min_dist = 100; + + //-- Quick calculation of max and min distances between keypoints + for( int i = 0; i < descriptors_1.rows; i++ ) + { double dist = matches[i].distance; + if( dist < min_dist ) min_dist = dist; + if( dist > max_dist ) max_dist = dist; + } + + printf("-- Max dist : %f \n", max_dist ); + printf("-- Min dist : %f \n", min_dist ); + + //-- Draw only "good" matches (i.e. whose distance is less than 2*min_dist ) + //-- PS.- radiusMatch can also be used here. + std::vector< DMatch > good_matches; + + for( int i = 0; i < descriptors_1.rows; i++ ) + { if( matches[i].distance < 2*min_dist ) + { good_matches.push_back( matches[i]); } + } + + //-- Draw only "good" matches + Mat img_matches; + drawMatches( img_1, keypoints_1, img_2, keypoints_2, + good_matches, img_matches, Scalar::all(-1), Scalar::all(-1), + vector(), DrawMatchesFlags::NOT_DRAW_SINGLE_POINTS ); + + //-- Show detected matches + imshow( "Good Matches", img_matches ); + + for( int i = 0; i < good_matches.size(); i++ ) + { printf( "-- Good Match [%d] Keypoint 1: %d -- Keypoint 2: %d \n", i, good_matches[i].queryIdx, good_matches[i].trainIdx ); } + + waitKey(0); + + return 0; + } + + /** @function readme */ + void readme() + { std::cout << " Usage: ./SURF_FlannMatcher " << std::endl; } + +Explanation +============ + +Result +====== + +#. Here is the result of the feature detection applied to the first image: + + .. image:: images/Featur_FlannMatcher_Result.jpg + :align: center + :height: 250pt + +#. Additionally, we get as console output the keypoints filtered: + + .. image:: images/Feature_FlannMatcher_Keypoints_Result.jpg + :align: center + :height: 250pt + + + diff --git a/doc/tutorials/features2d/feature_flann_matcher/images/Featur_FlannMatcher_Result.jpg b/doc/tutorials/features2d/feature_flann_matcher/images/Featur_FlannMatcher_Result.jpg new file mode 100644 index 000000000..e3f66fa0d Binary files /dev/null and b/doc/tutorials/features2d/feature_flann_matcher/images/Featur_FlannMatcher_Result.jpg differ diff --git a/doc/tutorials/features2d/feature_flann_matcher/images/Feature_FlannMatcher_Keypoints_Result.jpg b/doc/tutorials/features2d/feature_flann_matcher/images/Feature_FlannMatcher_Keypoints_Result.jpg new file mode 100644 index 000000000..7648e5860 Binary files /dev/null and b/doc/tutorials/features2d/feature_flann_matcher/images/Feature_FlannMatcher_Keypoints_Result.jpg differ diff --git a/doc/tutorials/features2d/table_of_content_features2d/images/Feature_Flann_Matcher_Tutorial_Cover.jpg b/doc/tutorials/features2d/table_of_content_features2d/images/Feature_Flann_Matcher_Tutorial_Cover.jpg new file mode 100644 index 000000000..e3f66fa0d Binary files /dev/null and b/doc/tutorials/features2d/table_of_content_features2d/images/Feature_Flann_Matcher_Tutorial_Cover.jpg differ diff --git a/samples/cpp/tutorial_code/features2D/SURF_FlannMatcher.cpp b/samples/cpp/tutorial_code/features2D/SURF_FlannMatcher.cpp index 2e3c1eba2..b7bc0de4b 100644 --- a/samples/cpp/tutorial_code/features2D/SURF_FlannMatcher.cpp +++ b/samples/cpp/tutorial_code/features2D/SURF_FlannMatcher.cpp @@ -94,4 +94,4 @@ int main( int argc, char** argv ) * @function readme */ void readme() -{ std::cout << " Usage: ./SURF_descriptor " << std::endl; } +{ std::cout << " Usage: ./SURF_FlannMatcher " << std::endl; } diff --git a/samples/cpp/tutorial_code/features2D/SURF_Homography.cpp b/samples/cpp/tutorial_code/features2D/SURF_Homography.cpp index 8194a498d..da595bcf0 100644 --- a/samples/cpp/tutorial_code/features2D/SURF_Homography.cpp +++ b/samples/cpp/tutorial_code/features2D/SURF_Homography.cpp @@ -119,4 +119,4 @@ int main( int argc, char** argv ) * @function readme */ void readme() -{ std::cout << " Usage: ./SURF_descriptor " << std::endl; } +{ std::cout << " Usage: ./SURF_Homography " << std::endl; }