AKAZE fixes, tests and tutorial

doc/tutorials/features2d/akaze_matching/akaze_matching.rst

@@ -0,0 +1,161 @@
+.. _akazeMatching:
+
+
+AKAZE local features matching
+******************************
+
+Introduction
+------------------
+
+In this tutorial we will learn how to use [AKAZE]_ local features to detect and match keypoints on two images.
+
+We will find keypoints on a pair of images with given homography matrix,
+match them and count the number of inliers (i. e. matches that fit in the given homography).
+
+You can find expanded version of this example here: https://github.com/pablofdezalc/test_kaze_akaze_opencv
+
+.. [AKAZE] Fast Explicit Diffusion for Accelerated Features in Nonlinear Scale Spaces. Pablo F. Alcantarilla, Jesús Nuevo and Adrien Bartoli. In British Machine Vision Conference (BMVC), Bristol, UK, September 2013.
+
+Data
+------------------
+We are going to use images 1 and 3 from *Graffity* sequence of Oxford dataset.
+
+.. image:: images/graf.png
+  :height: 200pt
+  :width:  320pt
+  :alt: Graffity
+  :align: center
+
+Homography is given by a 3 by 3 matrix:
+
+.. code-block:: none
+
+    7.6285898e-01  -2.9922929e-01   2.2567123e+02
+    3.3443473e-01   1.0143901e+00  -7.6999973e+01
+    3.4663091e-04  -1.4364524e-05   1.0000000e+00
+
+You can find the images (*graf1.png*, *graf3.png*) and homography (*H1to3p.xml*) in *opencv/samples/cpp*.
+
+Source Code
+===========
+.. literalinclude:: ../../../../samples/cpp/tutorial_code/features2D/AKAZE_match.cpp
+   :language: cpp
+   :linenos:
+   :tab-width: 4
+
+Explanation
+===========
+
+1. **Load images and homography**
+
+  .. code-block:: cpp
+
+    Mat img1 = imread("graf1.png", IMREAD_GRAYSCALE);
+    Mat img2 = imread("graf3.png", IMREAD_GRAYSCALE);
+
+    Mat homography;
+    FileStorage fs("H1to3p.xml", FileStorage::READ);
+    fs.getFirstTopLevelNode() >> homography;
+
+  We are loading grayscale images here. Homography is stored in the xml created with FileStorage.
+
+2. **Detect keypoints and compute descriptors using AKAZE**
+
+  .. code-block:: cpp
+
+    vector<KeyPoint> kpts1, kpts2;
+    Mat desc1, desc2;
+
+    AKAZE akaze;
+    akaze(img1, noArray(), kpts1, desc1);
+    akaze(img2, noArray(), kpts2, desc2);
+
+  We create AKAZE object and use it's *operator()* functionality. Since we don't need the *mask* parameter, *noArray()* is used.
+
+3. **Use brute-force matcher to find 2-nn matches**
+
+  .. code-block:: cpp
+
+    BFMatcher matcher(NORM_HAMMING);
+    vector< vector<DMatch> > nn_matches;
+    matcher.knnMatch(desc1, desc2, nn_matches, 2);
+
+  We use Hamming distance, because AKAZE uses binary descriptor by default.
+
+4. **Use 2-nn matches to find correct keypoint matches**
+
+  .. code-block:: cpp
+
+    for(size_t i = 0; i < nn_matches.size(); i++) {
+        DMatch first = nn_matches[i][0];
+        float dist1 = nn_matches[i][0].distance;
+        float dist2 = nn_matches[i][1].distance;
+
+        if(dist1 < nn_match_ratio * dist2) {
+            matched1.push_back(kpts1[first.queryIdx]);
+            matched2.push_back(kpts2[first.trainIdx]);
+        }
+    }
+
+  If the closest match is *ratio* closer than the second closest one, then the match is correct.
+
+5. **Check if our matches fit in the homography model**
+
+  .. code-block:: cpp
+
+    for(int i = 0; i < matched1.size(); i++) {
+        Mat col = Mat::ones(3, 1, CV_64F);
+        col.at<double>(0) = matched1[i].pt.x;
+        col.at<double>(1) = matched1[i].pt.y;
+
+        col = homography * col;
+        col /= col.at<double>(2);
+        float dist = sqrt( pow(col.at<double>(0) - matched2[i].pt.x, 2) +
+                           pow(col.at<double>(1) - matched2[i].pt.y, 2));
+
+        if(dist < inlier_threshold) {
+            int new_i = inliers1.size();
+            inliers1.push_back(matched1[i]);
+            inliers2.push_back(matched2[i]);
+            good_matches.push_back(DMatch(new_i, new_i, 0));
+        }
+    }
+
+  If the distance from first keypoint's projection to the second keypoint is less than threshold, then it it fits in the homography.
+
+  We create a new set of matches for the inliers, because it is required by the drawing function.
+
+6. **Output results**
+
+  .. code-block:: cpp
+
+    Mat res;
+    drawMatches(img1, inliers1, img2, inliers2, good_matches, res);
+    imwrite("res.png", res);
+    ...
+
+  Here we save the resulting image and print some statistics.
+
+Results
+=======
+
+Found matches
+--------------
+
+.. image:: images/res.png
+  :height: 200pt
+  :width:  320pt
+  :alt: Matches
+  :align: center
+
+A-KAZE Matching Results
+--------------------------
+Keypoints 1:                        	2943
+
+Keypoints 2:                        	3511
+
+Matches:                            	447
+
+Inliers:                            	308
+
+Inliers Ratio:                      	0.689038

doc/tutorials/features2d/table_of_content_features2d/table_of_content_features2d.rst

@@ -183,6 +183,25 @@ Learn about how to use the feature points  detectors, descriptors and matching f
                      :height: 90pt
                      :width:  90pt
 
++
+  .. tabularcolumns:: m{100pt} m{300pt}
+  .. cssclass:: toctableopencv
+
+  ===================== ==============================================
+   |AkazeMatch|         **Title:** :ref:`akazeMatching`
+
+                        *Compatibility:* > OpenCV 3.0
+
+                        *Author:* Fedor Morozov
+
+                        Use *AKAZE* local features to find correspondence between two images.
+
+  ===================== ==============================================
+
+  .. |AkazeMatch| image:: images/AKAZE_Match_Tutorial_Cover.png
+                     :height: 90pt
+                     :width:  90pt
+
 .. raw:: latex
 
    \pagebreak
@@ -201,3 +220,4 @@ Learn about how to use the feature points  detectors, descriptors and matching f
    ../feature_flann_matcher/feature_flann_matcher
    ../feature_homography/feature_homography
    ../detection_of_planar_objects/detection_of_planar_objects
+   ../akaze_matching/akaze_matching

modules/features2d/doc/feature_detection_and_description.rst

@@ -31,7 +31,7 @@ Detects corners using the FAST algorithm
 
 Detects corners using the FAST algorithm by [Rosten06]_.
 
-..note:: In Python API, types are given as ``cv2.FAST_FEATURE_DETECTOR_TYPE_5_8``, ``cv2.FAST_FEATURE_DETECTOR_TYPE_7_12`` and  ``cv2.FAST_FEATURE_DETECTOR_TYPE_9_16``. For corner detection, use ``cv2.FAST.detect()`` method.
+.. note:: In Python API, types are given as ``cv2.FAST_FEATURE_DETECTOR_TYPE_5_8``, ``cv2.FAST_FEATURE_DETECTOR_TYPE_7_12`` and  ``cv2.FAST_FEATURE_DETECTOR_TYPE_9_16``. For corner detection, use ``cv2.FAST.detect()`` method.
 
 
 .. [Rosten06] E. Rosten. Machine Learning for High-speed Corner Detection, 2006.
@@ -254,7 +254,17 @@ KAZE
 ----
 .. ocv:class:: KAZE : public Feature2D
 
-Class implementing the KAZE keypoint detector and descriptor extractor, described in [ABD12]_.
+Class implementing the KAZE keypoint detector and descriptor extractor, described in [ABD12]_. ::
+
+    class CV_EXPORTS_W KAZE : public Feature2D
+    {
+    public:
+        CV_WRAP KAZE();
+        CV_WRAP explicit KAZE(bool extended, bool upright, float threshold = 0.001f,
+                              int octaves = 4, int sublevels = 4, int diffusivity = DIFF_PM_G2);
+    };
+
+.. note:: AKAZE descriptor can only be used with KAZE or AKAZE keypoints
 
 .. [ABD12] KAZE Features. Pablo F. Alcantarilla, Adrien Bartoli and Andrew J. Davison. In European Conference on Computer Vision (ECCV), Fiorenze, Italy, October 2012.
 
@@ -262,12 +272,14 @@ KAZE::KAZE
 ----------
 The KAZE constructor
 
-.. ocv:function:: KAZE::KAZE(bool extended, bool upright)
+.. ocv:function:: KAZE::KAZE(bool extended, bool upright, float threshold, int octaves, int sublevels, int diffusivity)
 
     :param extended: Set to enable extraction of extended (128-byte) descriptor.
     :param upright: Set to enable use of upright descriptors (non rotation-invariant).
-
+    :param threshold: Detector response threshold to accept point
-
+    :param octaves: Maximum octave evolution of the image
+    :param sublevels: Default number of sublevels per scale level
+    :param diffusivity: Diffusivity type. DIFF_PM_G1, DIFF_PM_G2, DIFF_WEICKERT or DIFF_CHARBONNIER
 
 AKAZE
 -----
@@ -278,25 +290,25 @@ Class implementing the AKAZE keypoint detector and descriptor extractor, describ
     class CV_EXPORTS_W AKAZE : public Feature2D
     {
     public:
-        /// AKAZE Descriptor Type
-        enum DESCRIPTOR_TYPE {
-            DESCRIPTOR_KAZE_UPRIGHT = 2, ///< Upright descriptors, not invariant to rotation
-            DESCRIPTOR_KAZE = 3,
-            DESCRIPTOR_MLDB_UPRIGHT = 4, ///< Upright descriptors, not invariant to rotation
-            DESCRIPTOR_MLDB = 5
-        };
         CV_WRAP AKAZE();
-        explicit AKAZE(DESCRIPTOR_TYPE descriptor_type, int descriptor_size = 0, int descriptor_channels = 3);
+        CV_WRAP explicit AKAZE(int descriptor_type, int descriptor_size = 0, int descriptor_channels = 3,
+                               float threshold = 0.001f, int octaves = 4, int sublevels = 4, int diffusivity = DIFF_PM_G2);
     };
 
+.. note:: AKAZE descriptor can only be used with KAZE or AKAZE keypoints
+
 .. [ANB13] Fast Explicit Diffusion for Accelerated Features in Nonlinear Scale Spaces. Pablo F. Alcantarilla, Jesús Nuevo and Adrien Bartoli. In British Machine Vision Conference (BMVC), Bristol, UK, September 2013.
 
 AKAZE::AKAZE
 ------------
 The AKAZE constructor
 
-.. ocv:function:: AKAZE::AKAZE(DESCRIPTOR_TYPE descriptor_type, int descriptor_size = 0, int descriptor_channels = 3)
+.. ocv:function:: AKAZE::AKAZE(int descriptor_type, int descriptor_size, int descriptor_channels, float threshold, int octaves, int sublevels, int diffusivity)
 
-    :param descriptor_type: Type of the extracted descriptor.
+    :param descriptor_type: Type of the extracted descriptor: DESCRIPTOR_KAZE, DESCRIPTOR_KAZE_UPRIGHT, DESCRIPTOR_MLDB or DESCRIPTOR_MLDB_UPRIGHT.
     :param descriptor_size: Size of the descriptor in bits. 0 -> Full size
-    :param descriptor_channels: Number of channels in the descriptor (1, 2, 3).
+    :param descriptor_channels: Number of channels in the descriptor (1, 2, 3)
+    :param threshold: Detector response threshold to accept point
+    :param octaves: Maximum octave evolution of the image
+    :param sublevels: Default number of sublevels per scale level
+    :param diffusivity: Diffusivity type. DIFF_PM_G1, DIFF_PM_G2, DIFF_WEICKERT or DIFF_CHARBONNIER

modules/features2d/include/opencv2/features2d.hpp

@@ -895,6 +895,22 @@ protected:
     PixelTestFn test_fn_;
 };
 
+// KAZE/AKAZE diffusivity
+enum {
+    DIFF_PM_G1 = 0,
+    DIFF_PM_G2 = 1,
+    DIFF_WEICKERT = 2,
+    DIFF_CHARBONNIER = 3
+};
+
+// AKAZE descriptor type
+enum {
+    DESCRIPTOR_KAZE_UPRIGHT = 2, ///< Upright descriptors, not invariant to rotation
+    DESCRIPTOR_KAZE = 3,
+    DESCRIPTOR_MLDB_UPRIGHT = 4, ///< Upright descriptors, not invariant to rotation
+    DESCRIPTOR_MLDB = 5
+};
+
 /*!
 KAZE implementation
 */
@@ -902,7 +918,8 @@ class CV_EXPORTS_W KAZE : public Feature2D
 {
 public:
     CV_WRAP KAZE();
-    CV_WRAP explicit KAZE(bool extended, bool upright);
+    CV_WRAP explicit KAZE(bool extended, bool upright, float threshold = 0.001f,
+                          int octaves = 4, int sublevels = 4, int diffusivity = DIFF_PM_G2);
 
     virtual ~KAZE();
 
@@ -928,6 +945,10 @@ protected:
 
     CV_PROP bool extended;
     CV_PROP bool upright;
+    CV_PROP float threshold;
+    CV_PROP int octaves;
+    CV_PROP int sublevels;
+    CV_PROP int diffusivity;
 };
 
 /*!
@@ -936,16 +957,9 @@ AKAZE implementation
 class CV_EXPORTS_W AKAZE : public Feature2D
 {
 public:
-    /// AKAZE Descriptor Type
-    enum DESCRIPTOR_TYPE {
-        DESCRIPTOR_KAZE_UPRIGHT = 2, ///< Upright descriptors, not invariant to rotation
-        DESCRIPTOR_KAZE = 3,
-        DESCRIPTOR_MLDB_UPRIGHT = 4, ///< Upright descriptors, not invariant to rotation
-        DESCRIPTOR_MLDB = 5
-    };
-
     CV_WRAP AKAZE();
-    explicit AKAZE(DESCRIPTOR_TYPE descriptor_type, int descriptor_size = 0, int descriptor_channels = 3);
+    CV_WRAP explicit AKAZE(int descriptor_type, int descriptor_size = 0, int descriptor_channels = 3,
+                   float threshold = 0.001f, int octaves = 4, int sublevels = 4, int diffusivity = DIFF_PM_G2);
 
     virtual ~AKAZE();
 
@@ -973,7 +987,10 @@ protected:
     CV_PROP int descriptor;
     CV_PROP int descriptor_channels;
     CV_PROP int descriptor_size;
-
+    CV_PROP float threshold;
+    CV_PROP int octaves;
+    CV_PROP int sublevels;
+    CV_PROP int diffusivity;
 };
 /****************************************************************************************\
 *                                      Distance                                          *

modules/features2d/src/akaze.cpp

@@ -49,7 +49,10 @@ http://www.robesafe.com/personal/pablo.alcantarilla/papers/Alcantarilla13bmvc.pd
 */
 
 #include "precomp.hpp"
-#include "akaze/AKAZEFeatures.h"
+#include "kaze/AKAZEFeatures.h"
+
+#include <iostream>
+using namespace std;
 
 namespace cv
 {
@@ -57,13 +60,22 @@ namespace cv
         : descriptor(DESCRIPTOR_MLDB)
         , descriptor_channels(3)
         , descriptor_size(0)
+        , threshold(0.001f)
+        , octaves(4)
+        , sublevels(4)
+        , diffusivity(DIFF_PM_G2)
     {
     }
 
-    AKAZE::AKAZE(DESCRIPTOR_TYPE _descriptor_type, int _descriptor_size, int _descriptor_channels)
+    AKAZE::AKAZE(int _descriptor_type, int _descriptor_size, int _descriptor_channels,
+                 float _threshold, int _octaves, int _sublevels, int _diffusivity)
         : descriptor(_descriptor_type)
         , descriptor_channels(_descriptor_channels)
         , descriptor_size(_descriptor_size)
+        , threshold(_threshold)
+        , octaves(_octaves)
+        , sublevels(_sublevels)
+        , diffusivity(_diffusivity)
     {
 
     }
@@ -78,12 +90,12 @@ namespace cv
     {
         switch (descriptor)
         {
-        case cv::AKAZE::DESCRIPTOR_KAZE:
+        case cv::DESCRIPTOR_KAZE:
-        case cv::AKAZE::DESCRIPTOR_KAZE_UPRIGHT:
+        case cv::DESCRIPTOR_KAZE_UPRIGHT:
             return 64;
 
-        case cv::AKAZE::DESCRIPTOR_MLDB:
+        case cv::DESCRIPTOR_MLDB:
-        case cv::AKAZE::DESCRIPTOR_MLDB_UPRIGHT:
+        case cv::DESCRIPTOR_MLDB_UPRIGHT:
             // We use the full length binary descriptor -> 486 bits
             if (descriptor_size == 0)
             {
@@ -106,12 +118,12 @@ namespace cv
     {
         switch (descriptor)
         {
-        case cv::AKAZE::DESCRIPTOR_KAZE:
+        case cv::DESCRIPTOR_KAZE:
-        case cv::AKAZE::DESCRIPTOR_KAZE_UPRIGHT:
+        case cv::DESCRIPTOR_KAZE_UPRIGHT:
                 return CV_32F;
 
-        case cv::AKAZE::DESCRIPTOR_MLDB:
+        case cv::DESCRIPTOR_MLDB:
-        case cv::AKAZE::DESCRIPTOR_MLDB_UPRIGHT:
+        case cv::DESCRIPTOR_MLDB_UPRIGHT:
                 return CV_8U;
 
             default:
@@ -124,12 +136,12 @@ namespace cv
     {
         switch (descriptor)
         {
-        case cv::AKAZE::DESCRIPTOR_KAZE:
+        case cv::DESCRIPTOR_KAZE:
-        case cv::AKAZE::DESCRIPTOR_KAZE_UPRIGHT:
+        case cv::DESCRIPTOR_KAZE_UPRIGHT:
             return cv::NORM_L2;
 
-        case cv::AKAZE::DESCRIPTOR_MLDB:
+        case cv::DESCRIPTOR_MLDB:
-        case cv::AKAZE::DESCRIPTOR_MLDB_UPRIGHT:
+        case cv::DESCRIPTOR_MLDB_UPRIGHT:
             return cv::NORM_HAMMING;
 
         default:
@@ -153,11 +165,15 @@ namespace cv
         cv::Mat& desc = descriptors.getMatRef();
 
         AKAZEOptions options;
-        options.descriptor = static_cast<DESCRIPTOR_TYPE>(descriptor);
+        options.descriptor = descriptor;
         options.descriptor_channels = descriptor_channels;
         options.descriptor_size = descriptor_size;
         options.img_width = img.cols;
         options.img_height = img.rows;
+        options.dthreshold = threshold;
+        options.omax = octaves;
+        options.nsublevels = sublevels;
+        options.diffusivity = diffusivity;
 
         AKAZEFeatures impl(options);
         impl.Create_Nonlinear_Scale_Space(img1_32);
@@ -188,7 +204,7 @@ namespace cv
         img.convertTo(img1_32, CV_32F, 1.0 / 255.0, 0);
 
         AKAZEOptions options;
-        options.descriptor = static_cast<DESCRIPTOR_TYPE>(descriptor);
+        options.descriptor = descriptor;
         options.descriptor_channels = descriptor_channels;
         options.descriptor_size = descriptor_size;
         options.img_width = img.cols;
@@ -216,7 +232,7 @@ namespace cv
         cv::Mat& desc = descriptors.getMatRef();
 
         AKAZEOptions options;
-        options.descriptor = static_cast<DESCRIPTOR_TYPE>(descriptor);
+        options.descriptor = descriptor;
         options.descriptor_channels = descriptor_channels;
         options.descriptor_size = descriptor_size;
         options.img_width = img.cols;
@@ -229,4 +245,4 @@ namespace cv
         CV_Assert((!desc.rows || desc.cols == descriptorSize()));
         CV_Assert((!desc.rows || (desc.type() == descriptorType())));
     }
-}
+}

modules/features2d/src/akaze/AKAZEFeatures.h

@@ -1,65 +0,0 @@
-/**
- * @file AKAZE.h
- * @brief Main class for detecting and computing binary descriptors in an
- * accelerated nonlinear scale space
- * @date Mar 27, 2013
- * @author Pablo F. Alcantarilla, Jesus Nuevo
- */
-
-#pragma once
-
-/* ************************************************************************* */
-// Includes
-#include "precomp.hpp"
-#include "AKAZEConfig.h"
-
-/* ************************************************************************* */
-// AKAZE Class Declaration
-class AKAZEFeatures {
-
-private:
-
-    AKAZEOptions options_;                ///< Configuration options for AKAZE
-    std::vector<TEvolution> evolution_;	///< Vector of nonlinear diffusion evolution
-
-    /// FED parameters
-    int ncycles_;                  ///< Number of cycles
-    bool reordering_;              ///< Flag for reordering time steps
-    std::vector<std::vector<float > > tsteps_;  ///< Vector of FED dynamic time steps
-    std::vector<int> nsteps_;      ///< Vector of number of steps per cycle
-
-    /// Matrices for the M-LDB descriptor computation
-    cv::Mat descriptorSamples_;  // List of positions in the grids to sample LDB bits from.
-    cv::Mat descriptorBits_;
-    cv::Mat bitMask_;
-
-public:
-
-    /// Constructor with input arguments
-    AKAZEFeatures(const AKAZEOptions& options);
-
-    /// Scale Space methods
-    void Allocate_Memory_Evolution();
-    int Create_Nonlinear_Scale_Space(const cv::Mat& img);
-    void Feature_Detection(std::vector<cv::KeyPoint>& kpts);
-    void Compute_Determinant_Hessian_Response(void);
-    void Compute_Multiscale_Derivatives(void);
-    void Find_Scale_Space_Extrema(std::vector<cv::KeyPoint>& kpts);
-    void Do_Subpixel_Refinement(std::vector<cv::KeyPoint>& kpts);
-
-    // Feature description methods
-    void Compute_Descriptors(std::vector<cv::KeyPoint>& kpts, cv::Mat& desc);
-
-    static void Compute_Main_Orientation(cv::KeyPoint& kpt, const std::vector<TEvolution>& evolution_);
-};
-
-/* ************************************************************************* */
-// Inline functions
-
-// Inline functions
-void generateDescriptorSubsample(cv::Mat& sampleList, cv::Mat& comparisons,
-    int nbits, int pattern_size, int nchannels);
-float get_angle(float x, float y);
-float gaussian(float x, float y, float sigma);
-void check_descriptor_limits(int& x, int& y, int width, int height);
-int fRound(float flt);

modules/features2d/src/kaze.cpp

@@ -55,12 +55,21 @@ namespace cv
     KAZE::KAZE()
         : extended(false)
         , upright(false)
+        , threshold(0.001f)
+        , octaves(4)
+        , sublevels(4)
+        , diffusivity(DIFF_PM_G2)
     {
     }
 
-    KAZE::KAZE(bool _extended, bool _upright)
+    KAZE::KAZE(bool _extended, bool _upright, float _threshold, int _octaves,
+               int _sublevels, int _diffusivity)
         : extended(_extended)
         , upright(_upright)
+        , threshold(_threshold)
+        , octaves(_octaves)
+        , sublevels(_sublevels)
+        , diffusivity(_diffusivity)
     {
 
     }
@@ -111,6 +120,10 @@ namespace cv
         options.img_height = img.rows;
         options.extended = extended;
         options.upright = upright;
+        options.dthreshold = threshold;
+        options.omax = octaves;
+        options.nsublevels = sublevels;
+        options.diffusivity = diffusivity;
 
         KAZEFeatures impl(options);
         impl.Create_Nonlinear_Scale_Space(img1_32);
@@ -180,4 +193,4 @@ namespace cv
         CV_Assert((!desc.rows || desc.cols == descriptorSize()));
         CV_Assert((!desc.rows || (desc.type() == descriptorType())));
     }
-}
+}

modules/features2d/src/kaze/AKAZEConfig.h

@@ -5,7 +5,8 @@
  * @author Pablo F. Alcantarilla, Jesus Nuevo
  */
 
-#pragma once
+#ifndef __OPENCV_FEATURES_2D_AKAZE_CONFIG_H__
+#define __OPENCV_FEATURES_2D_AKAZE_CONFIG_H__
 
 /* ************************************************************************* */
 // OpenCV
@@ -28,14 +29,6 @@ const float gauss25[7][7] = {
 /// AKAZE configuration options structure
 struct AKAZEOptions {
 
-    /// AKAZE Diffusivities
-    enum DIFFUSIVITY_TYPE {
-        PM_G1 = 0,
-        PM_G2 = 1,
-        WEICKERT = 2,
-        CHARBONNIER = 3
-    };
-
     AKAZEOptions()
         : omax(4)
         , nsublevels(4)
@@ -44,12 +37,12 @@ struct AKAZEOptions {
         , soffset(1.6f)
         , derivative_factor(1.5f)
         , sderivatives(1.0)
-        , diffusivity(PM_G2)
+        , diffusivity(cv::DIFF_PM_G2)
 
         , dthreshold(0.001f)
         , min_dthreshold(0.00001f)
 
-        , descriptor(cv::AKAZE::DESCRIPTOR_MLDB)
+        , descriptor(cv::DESCRIPTOR_MLDB)
         , descriptor_size(0)
         , descriptor_channels(3)
         , descriptor_pattern_size(10)
@@ -67,12 +60,12 @@ struct AKAZEOptions {
     float soffset;                  ///< Base scale offset (sigma units)
     float derivative_factor;        ///< Factor for the multiscale derivatives
     float sderivatives;             ///< Smoothing factor for the derivatives
-    DIFFUSIVITY_TYPE diffusivity;   ///< Diffusivity type
+    int diffusivity;   ///< Diffusivity type
 
     float dthreshold;               ///< Detector response threshold to accept point
     float min_dthreshold;           ///< Minimum detector threshold to accept a point
 
-    cv::AKAZE::DESCRIPTOR_TYPE descriptor;     ///< Type of descriptor
+    int descriptor;     ///< Type of descriptor
     int descriptor_size;            ///< Size of the descriptor in bits. 0->Full size
     int descriptor_channels;        ///< Number of channels in the descriptor (1, 2, 3)
     int descriptor_pattern_size;    ///< Actual patch size is 2*pattern_size*point.scale
@@ -82,28 +75,4 @@ struct AKAZEOptions {
     int kcontrast_nbins;            ///< Number of bins for the contrast factor histogram
 };
 
-/* ************************************************************************* */
+#endif
-/// AKAZE nonlinear diffusion filtering evolution
-struct TEvolution {
-
-    TEvolution() {
-        etime = 0.0f;
-        esigma = 0.0f;
-        octave = 0;
-        sublevel = 0;
-        sigma_size = 0;
-    }
-
-    cv::Mat Lx, Ly;	// First order spatial derivatives
-    cv::Mat Lxx, Lxy, Lyy;	// Second order spatial derivatives
-    cv::Mat Lflow;	// Diffusivity image
-    cv::Mat Lt;	// Evolution image
-    cv::Mat Lsmooth; // Smoothed image
-    cv::Mat Lstep; // Evolution step update
-    cv::Mat Ldet; // Detector response
-    float etime;	// Evolution time
-    float esigma;	// Evolution sigma. For linear diffusion t = sigma^2 / 2
-    size_t octave;	// Image octave
-    size_t sublevel;	// Image sublevel in each octave
-    size_t sigma_size;	// Integer sigma. For computing the feature detector responses
-};

modules/features2d/src/kaze/AKAZEFeatures.h

@@ -0,0 +1,62 @@
+/**
+ * @file AKAZE.h
+ * @brief Main class for detecting and computing binary descriptors in an
+ * accelerated nonlinear scale space
+ * @date Mar 27, 2013
+ * @author Pablo F. Alcantarilla, Jesus Nuevo
+ */
+
+#ifndef __OPENCV_FEATURES_2D_AKAZE_FEATURES_H__
+#define __OPENCV_FEATURES_2D_AKAZE_FEATURES_H__
+
+/* ************************************************************************* */
+// Includes
+#include "precomp.hpp"
+#include "AKAZEConfig.h"
+#include "TEvolution.h"
+
+/* ************************************************************************* */
+// AKAZE Class Declaration
+class AKAZEFeatures {
+
+private:
+
+  AKAZEOptions options_;                ///< Configuration options for AKAZE
+    std::vector<TEvolution> evolution_;        ///< Vector of nonlinear diffusion evolution
+
+  /// FED parameters
+  int ncycles_;                  ///< Number of cycles
+  bool reordering_;              ///< Flag for reordering time steps
+  std::vector<std::vector<float > > tsteps_;  ///< Vector of FED dynamic time steps
+  std::vector<int> nsteps_;      ///< Vector of number of steps per cycle
+
+  /// Matrices for the M-LDB descriptor computation
+  cv::Mat descriptorSamples_;  // List of positions in the grids to sample LDB bits from.
+  cv::Mat descriptorBits_;
+  cv::Mat bitMask_;
+
+public:
+
+  /// Constructor with input arguments
+  AKAZEFeatures(const AKAZEOptions& options);
+
+  /// Scale Space methods
+  void Allocate_Memory_Evolution();
+  int Create_Nonlinear_Scale_Space(const cv::Mat& img);
+  void Feature_Detection(std::vector<cv::KeyPoint>& kpts);
+  void Compute_Determinant_Hessian_Response(void);
+  void Compute_Multiscale_Derivatives(void);
+  void Find_Scale_Space_Extrema(std::vector<cv::KeyPoint>& kpts);
+  void Do_Subpixel_Refinement(std::vector<cv::KeyPoint>& kpts);
+
+  /// Feature description methods
+  void Compute_Descriptors(std::vector<cv::KeyPoint>& kpts, cv::Mat& desc);
+  static void Compute_Main_Orientation(cv::KeyPoint& kpt, const std::vector<TEvolution>& evolution_);
+};
+
+/* ************************************************************************* */
+/// Inline functions
+void generateDescriptorSubsample(cv::Mat& sampleList, cv::Mat& comparisons,
+                                 int nbits, int pattern_size, int nchannels);
+
+#endif

modules/features2d/src/kaze/KAZEConfig.h

@@ -5,7 +5,8 @@
  * @author Pablo F. Alcantarilla
  */
 
-#pragma once
+#ifndef __OPENCV_FEATURES_2D_AKAZE_CONFIG_H__
+#define __OPENCV_FEATURES_2D_AKAZE_CONFIG_H__
 
 // OpenCV Includes
 #include "precomp.hpp"
@@ -15,14 +16,8 @@
 
 struct KAZEOptions {
 
-    enum DIFFUSIVITY_TYPE {
-        PM_G1 = 0,
-        PM_G2 = 1,
-        WEICKERT = 2
-    };
-
     KAZEOptions()
-        : diffusivity(PM_G2)
+        : diffusivity(cv::DIFF_PM_G2)
 
         , soffset(1.60f)
         , omax(4)
@@ -33,20 +28,13 @@ struct KAZEOptions {
         , dthreshold(0.001f)
         , kcontrast(0.01f)
         , kcontrast_percentille(0.7f)
-        , kcontrast_bins(300)
+                , kcontrast_bins(300)
-
-        , use_fed(true)
         , upright(false)
         , extended(false)
-
-        , use_clipping_normalilzation(false)
-        , clipping_normalization_ratio(1.6f)
-        , clipping_normalization_niter(5)
     {
     }
 
-    DIFFUSIVITY_TYPE diffusivity;
+    int diffusivity;
-
     float soffset;
     int omax;
     int nsublevels;
@@ -57,27 +45,8 @@ struct KAZEOptions {
     float kcontrast;
     float kcontrast_percentille;
     int  kcontrast_bins;
-
-    bool use_fed;
     bool upright;
     bool extended;
-
-    bool  use_clipping_normalilzation;
-    float clipping_normalization_ratio;
-    int   clipping_normalization_niter;
 };
 
-struct TEvolution {
+#endif
-    cv::Mat Lx, Ly;	// First order spatial derivatives
-    cv::Mat Lxx, Lxy, Lyy;	// Second order spatial derivatives
-    cv::Mat Lflow;	// Diffusivity image
-    cv::Mat Lt;	// Evolution image
-    cv::Mat Lsmooth; // Smoothed image
-    cv::Mat Lstep; // Evolution step update
-    cv::Mat Ldet; // Detector response
-    float etime;	// Evolution time
-    float esigma;	// Evolution sigma. For linear diffusion t = sigma^2 / 2
-    float octave;	// Image octave
-    float sublevel;	// Image sublevel in each octave
-    int sigma_size;	// Integer esigma. For computing the feature detector responses
-};

modules/features2d/src/kaze/KAZEFeatures.h

@@ -7,84 +7,53 @@
  * @author Pablo F. Alcantarilla
  */
 
-#ifndef KAZE_H_
+#ifndef __OPENCV_FEATURES_2D_KAZE_FEATURES_H__
-#define KAZE_H_
+#define __OPENCV_FEATURES_2D_KAZE_FEATURES_H__
-
-//*************************************************************************************
-//*************************************************************************************
 
+/* ************************************************************************* */
 // Includes
 #include "KAZEConfig.h"
 #include "nldiffusion_functions.h"
 #include "fed.h"
+#include "TEvolution.h"
 
-//*************************************************************************************
+/* ************************************************************************* */
-//*************************************************************************************
-
 // KAZE Class Declaration
 class KAZEFeatures {
 
 private:
 
-    KAZEOptions options;
+        /// Parameters of the Nonlinear diffusion class
-
+        KAZEOptions options_;               ///< Configuration options for KAZE
-    // Parameters of the Nonlinear diffusion class
+        std::vector<TEvolution> evolution_;    ///< Vector of nonlinear diffusion evolution
-    std::vector<TEvolution> evolution_;	// Vector of nonlinear diffusion evolution
 
-    // Vector of keypoint vectors for finding extrema in multiple threads
+        /// Vector of keypoint vectors for finding extrema in multiple threads
     std::vector<std::vector<cv::KeyPoint> > kpts_par_;
 
-    // FED parameters
+        /// FED parameters
-    int ncycles_;                  // Number of cycles
+        int ncycles_;                  ///< Number of cycles
-    bool reordering_;              // Flag for reordering time steps
+        bool reordering_;              ///< Flag for reordering time steps
-    std::vector<std::vector<float > > tsteps_;  // Vector of FED dynamic time steps
+        std::vector<std::vector<float > > tsteps_;  ///< Vector of FED dynamic time steps
-    std::vector<int> nsteps_;      // Vector of number of steps per cycle
+        std::vector<int> nsteps_;      ///< Vector of number of steps per cycle
-
-    // Some auxiliary variables used in the AOS step
-    cv::Mat Ltx_, Lty_, px_, py_, ax_, ay_, bx_, by_, qr_, qc_;
 
 public:
 
-    // Constructor
+        /// Constructor
     KAZEFeatures(KAZEOptions& options);
 
-    // Public methods for KAZE interface
+        /// Public methods for KAZE interface
     void Allocate_Memory_Evolution(void);
     int Create_Nonlinear_Scale_Space(const cv::Mat& img);
     void Feature_Detection(std::vector<cv::KeyPoint>& kpts);
     void Feature_Description(std::vector<cv::KeyPoint>& kpts, cv::Mat& desc);
-
     static void Compute_Main_Orientation(cv::KeyPoint& kpt, const std::vector<TEvolution>& evolution_, const KAZEOptions& options);
 
-private:
+        /// Feature Detection Methods
-
-    // Feature Detection Methods
     void Compute_KContrast(const cv::Mat& img, const float& kper);
     void Compute_Multiscale_Derivatives(void);
     void Compute_Detector_Response(void);
-    void Determinant_Hessian_Parallel(std::vector<cv::KeyPoint>& kpts);
+        void Determinant_Hessian(std::vector<cv::KeyPoint>& kpts);
-    void Find_Extremum_Threading(const int& level);
     void Do_Subpixel_Refinement(std::vector<cv::KeyPoint>& kpts);
-
-    // AOS Methods
-    void AOS_Step_Scalar(cv::Mat &Ld, const cv::Mat &Ldprev, const cv::Mat &c, const float& stepsize);
-    void AOS_Rows(const cv::Mat &Ldprev, const cv::Mat &c, const float& stepsize);
-    void AOS_Columns(const cv::Mat &Ldprev, const cv::Mat &c, const float& stepsize);
-    void Thomas(const cv::Mat &a, const cv::Mat &b, const cv::Mat &Ld, cv::Mat &x);
-
 };
 
-//*************************************************************************************
+#endif
-//*************************************************************************************
-
-// Inline functions
-float getAngle(const float& x, const float& y);
-float gaussian(const float& x, const float& y, const float& sig);
-void checkDescriptorLimits(int &x, int &y, const int& width, const int& height);
-void clippingDescriptor(float *desc, const int& dsize, const int& niter, const float& ratio);
-int fRound(const float& flt);
-
-//*************************************************************************************
-//*************************************************************************************
-
-#endif // KAZE_H_

modules/features2d/src/kaze/TEvolution.h

@@ -0,0 +1,35 @@
+/**
+ * @file TEvolution.h
+ * @brief Header file with the declaration of the TEvolution struct
+ * @date Jun 02, 2014
+ * @author Pablo F. Alcantarilla
+ */
+
+#ifndef __OPENCV_FEATURES_2D_TEVOLUTION_H__
+#define __OPENCV_FEATURES_2D_TEVOLUTION_H__
+
+/* ************************************************************************* */
+/// KAZE/A-KAZE nonlinear diffusion filtering evolution
+struct TEvolution {
+
+  TEvolution() {
+    etime = 0.0f;
+    esigma = 0.0f;
+    octave = 0;
+    sublevel = 0;
+    sigma_size = 0;
+  }
+
+  cv::Mat Lx, Ly;           ///< First order spatial derivatives
+  cv::Mat Lxx, Lxy, Lyy;    ///< Second order spatial derivatives
+  cv::Mat Lt;               ///< Evolution image
+  cv::Mat Lsmooth;          ///< Smoothed image
+  cv::Mat Ldet;             ///< Detector response
+  float etime;              ///< Evolution time
+  float esigma;             ///< Evolution sigma. For linear diffusion t = sigma^2 / 2
+  int octave;               ///< Image octave
+  int sublevel;             ///< Image sublevel in each octave
+  int sigma_size;           ///< Integer esigma. For computing the feature detector responses
+};
+
+#endif

modules/features2d/src/kaze/fed.h

@@ -1,5 +1,5 @@
-#ifndef FED_H
+#ifndef __OPENCV_FEATURES_2D_FED_H__
-#define FED_H
+#define __OPENCV_FEATURES_2D_FED_H__
 
 //******************************************************************************
 //******************************************************************************
@@ -22,4 +22,4 @@ bool fed_is_prime_internal(const int& number);
 //*************************************************************************************
 //*************************************************************************************
 
-#endif // FED_H
+#endif // __OPENCV_FEATURES_2D_FED_H__

modules/features2d/src/kaze/nldiffusion_functions.h

@@ -8,8 +8,8 @@
  * @author Pablo F. Alcantarilla
  */
 
-#ifndef KAZE_NLDIFFUSION_FUNCTIONS_H
+#ifndef __OPENCV_FEATURES_2D_NLDIFFUSION_FUNCTIONS_H__
-#define KAZE_NLDIFFUSION_FUNCTIONS_H
+#define __OPENCV_FEATURES_2D_NLDIFFUSION_FUNCTIONS_H__
 
 /* ************************************************************************* */
 // Includes

modules/features2d/src/kaze/utils.h

@@ -0,0 +1,77 @@
+#ifndef __OPENCV_FEATURES_2D_KAZE_UTILS_H__
+#define __OPENCV_FEATURES_2D_KAZE_UTILS_H__
+
+/* ************************************************************************* */
+/**
+ * @brief This function computes the angle from the vector given by (X Y). From 0 to 2*Pi
+ */
+inline float getAngle(float x, float y) {
+
+  if (x >= 0 && y >= 0) {
+    return atanf(y / x);
+  }
+
+  if (x < 0 && y >= 0) {
+    return static_cast<float>(CV_PI)-atanf(-y / x);
+  }
+
+  if (x < 0 && y < 0) {
+    return static_cast<float>(CV_PI)+atanf(y / x);
+  }
+
+  if (x >= 0 && y < 0) {
+    return static_cast<float>(2.0 * CV_PI) - atanf(-y / x);
+  }
+
+  return 0;
+}
+
+/* ************************************************************************* */
+/**
+ * @brief This function computes the value of a 2D Gaussian function
+ * @param x X Position
+ * @param y Y Position
+ * @param sig Standard Deviation
+ */
+inline float gaussian(float x, float y, float sigma) {
+  return expf(-(x*x + y*y) / (2.0f*sigma*sigma));
+}
+
+/* ************************************************************************* */
+/**
+ * @brief This function checks descriptor limits
+ * @param x X Position
+ * @param y Y Position
+ * @param width Image width
+ * @param height Image height
+ */
+inline void checkDescriptorLimits(int &x, int &y, int width, int height) {
+
+  if (x < 0) {
+    x = 0;
+  }
+
+  if (y < 0) {
+    y = 0;
+  }
+
+  if (x > width - 1) {
+    x = width - 1;
+  }
+
+  if (y > height - 1) {
+    y = height - 1;
+  }
+}
+
+/* ************************************************************************* */
+/**
+ * @brief This funtion rounds float to nearest integer
+ * @param flt Input float
+ * @return dst Nearest integer
+ */
+inline int fRound(float flt) {
+  return (int)(flt + 0.5f);
+}
+
+#endif

modules/features2d/test/test_descriptors_regression.cpp

@@ -101,8 +101,14 @@ public:
     typedef typename Distance::ResultType DistanceType;
 
     CV_DescriptorExtractorTest( const string _name, DistanceType _maxDist, const Ptr<DescriptorExtractor>& _dextractor,
-                                Distance d = Distance() ):
+                                Distance d = Distance(), Ptr<FeatureDetector> _detector = Ptr<FeatureDetector>()):
-            name(_name), maxDist(_maxDist), dextractor(_dextractor), distance(d) {}
+        name(_name), maxDist(_maxDist), dextractor(_dextractor), distance(d) , detector(_detector) {}
+
+    ~CV_DescriptorExtractorTest()
+    {
+        if(!detector.empty())
+            detector.release();
+    }
 protected:
     virtual void createDescriptorExtractor() {}
 
@@ -189,7 +195,6 @@ protected:
 
         // Read the test image.
         string imgFilename =  string(ts->get_data_path()) + FEATURES2D_DIR + "/" + IMAGE_FILENAME;
-
         Mat img = imread( imgFilename );
         if( img.empty() )
         {
@@ -197,13 +202,15 @@ protected:
             ts->set_failed_test_info( cvtest::TS::FAIL_INVALID_TEST_DATA );
             return;
         }
-
         vector<KeyPoint> keypoints;
         FileStorage fs( string(ts->get_data_path()) + FEATURES2D_DIR + "/keypoints.xml.gz", FileStorage::READ );
-        if( fs.isOpened() )
+        if(!detector.empty()) {
-        {
+            detector->detect(img, keypoints);
+        } else {
             read( fs.getFirstTopLevelNode(), keypoints );
-
+        }
+        if(!keypoints.empty())
+        {
             Mat calcDescriptors;
             double t = (double)getTickCount();
             dextractor->compute( img, keypoints, calcDescriptors );
@@ -244,7 +251,7 @@ protected:
                 }
             }
         }
-        else
+        if(!fs.isOpened())
         {
             ts->printf( cvtest::TS::LOG, "Compute and write keypoints.\n" );
             fs.open( string(ts->get_data_path()) + FEATURES2D_DIR + "/keypoints.xml.gz", FileStorage::WRITE );
@@ -295,6 +302,7 @@ protected:
     const DistanceType maxDist;
     Ptr<DescriptorExtractor> dextractor;
     Distance distance;
+    Ptr<FeatureDetector> detector;
 
 private:
     CV_DescriptorExtractorTest& operator=(const CV_DescriptorExtractorTest&) { return *this; }
@@ -340,3 +348,19 @@ TEST( Features2d_DescriptorExtractor_OpponentBRIEF, regression )
                                                DescriptorExtractor::create("OpponentBRIEF") );
     test.safe_run();
 }
+
+TEST( Features2d_DescriptorExtractor_KAZE, regression )
+{
+    CV_DescriptorExtractorTest< L2<float> > test( "descriptor-kaze",  0.03f,
+                                                 DescriptorExtractor::create("KAZE"),
+                                                 L2<float>(), FeatureDetector::create("KAZE"));
+    test.safe_run();
+}
+
+TEST( Features2d_DescriptorExtractor_AKAZE, regression )
+{
+    CV_DescriptorExtractorTest<Hamming> test( "descriptor-akaze",  (CV_DescriptorExtractorTest<Hamming>::DistanceType)12.f,
+                                              DescriptorExtractor::create("AKAZE"),
+                                              Hamming(), FeatureDetector::create("AKAZE"));
+    test.safe_run();
+}

modules/features2d/test/test_detectors_regression.cpp

@@ -289,6 +289,18 @@ TEST( Features2d_Detector_ORB, regression )
     test.safe_run();
 }
 
+TEST( Features2d_Detector_KAZE, regression )
+{
+    CV_FeatureDetectorTest test( "detector-kaze", FeatureDetector::create("KAZE") );
+    test.safe_run();
+}
+
+TEST( Features2d_Detector_AKAZE, regression )
+{
+    CV_FeatureDetectorTest test( "detector-akaze", FeatureDetector::create("AKAZE") );
+    test.safe_run();
+}
+
 TEST( Features2d_Detector_GridFAST, regression )
 {
     CV_FeatureDetectorTest test( "detector-grid-fast", FeatureDetector::create("GridFAST") );

modules/features2d/test/test_keypoints.cpp

@@ -167,19 +167,17 @@ TEST(Features2d_Detector_Keypoints_Dense, validation)
     test.safe_run();
 }
 
-// FIXIT #2807 Crash on Windows 7 x64 MSVS 2012, Linux Fedora 19 x64 with GCC 4.8.2, Linux Ubuntu 14.04 LTS x64 with GCC 4.8.2
+TEST(Features2d_Detector_Keypoints_KAZE, validation)
-TEST(Features2d_Detector_Keypoints_KAZE, DISABLED_validation)
 {
     CV_FeatureDetectorKeypointsTest test(Algorithm::create<FeatureDetector>("Feature2D.KAZE"));
     test.safe_run();
 }
 
-// FIXIT #2807 Crash on Windows 7 x64 MSVS 2012, Linux Fedora 19 x64 with GCC 4.8.2, Linux Ubuntu 14.04 LTS x64 with GCC 4.8.2
+TEST(Features2d_Detector_Keypoints_AKAZE, validation)
-TEST(Features2d_Detector_Keypoints_AKAZE, DISABLED_validation)
 {
-    CV_FeatureDetectorKeypointsTest test_kaze(cv::Ptr<FeatureDetector>(new cv::AKAZE(cv::AKAZE::DESCRIPTOR_KAZE)));
+    CV_FeatureDetectorKeypointsTest test_kaze(cv::Ptr<FeatureDetector>(new cv::AKAZE(cv::DESCRIPTOR_KAZE)));
     test_kaze.safe_run();
 
-    CV_FeatureDetectorKeypointsTest test_mldb(cv::Ptr<FeatureDetector>(new cv::AKAZE(cv::AKAZE::DESCRIPTOR_MLDB)));
+    CV_FeatureDetectorKeypointsTest test_mldb(cv::Ptr<FeatureDetector>(new cv::AKAZE(cv::DESCRIPTOR_MLDB)));
     test_mldb.safe_run();
 }

modules/features2d/test/test_rotation_and_scale_invariance.cpp

@@ -652,8 +652,7 @@ TEST(Features2d_ScaleInvariance_Detector_BRISK, regression)
     test.safe_run();
 }
 
-// FIXIT #2807 Crash on Windows 7 x64 MSVS 2012, Linux Fedora 19 x64 with GCC 4.8.2, Linux Ubuntu 14.04 LTS x64 with GCC 4.8.2
+TEST(Features2d_ScaleInvariance_Detector_KAZE, regression)
-TEST(Features2d_ScaleInvariance_Detector_KAZE, DISABLED_regression)
 {
     DetectorScaleInvarianceTest test(Algorithm::create<FeatureDetector>("Feature2D.KAZE"),
         0.08f,
@@ -661,8 +660,7 @@ TEST(Features2d_ScaleInvariance_Detector_KAZE, DISABLED_regression)
     test.safe_run();
 }
 
-// FIXIT #2807 Crash on Windows 7 x64 MSVS 2012, Linux Fedora 19 x64 with GCC 4.8.2, Linux Ubuntu 14.04 LTS x64 with GCC 4.8.2
+TEST(Features2d_ScaleInvariance_Detector_AKAZE, regression)
-TEST(Features2d_ScaleInvariance_Detector_AKAZE, DISABLED_regression)
 {
     DetectorScaleInvarianceTest test(Algorithm::create<FeatureDetector>("Feature2D.AKAZE"),
         0.08f,

samples/cpp/H1to3p.xml

@@ -0,0 +1,11 @@
+<?xml version="1.0"?>
+<opencv_storage>
+<H13 type_id="opencv-matrix">
+  <rows>3</rows>
+  <cols>3</cols>
+  <dt>d</dt>
+  <data>
+	7.6285898e-01  -2.9922929e-01   2.2567123e+02
+	3.3443473e-01   1.0143901e+00  -7.6999973e+01
+	3.4663091e-04  -1.4364524e-05   1.0000000e+00 </data></H13>
+</opencv_storage>

samples/cpp/tutorial_code/features2D/AKAZE_match.cpp

@@ -0,0 +1,79 @@
+#include <opencv2/features2d.hpp>
+#include <opencv2/imgcodecs.hpp>
+#include <opencv2/opencv.hpp>
+#include <vector>
+#include <iostream>
+
+using namespace std;
+using namespace cv;
+
+const float inlier_threshold = 2.5f; // Distance threshold to identify inliers
+const float nn_match_ratio = 0.8f;   // Nearest neighbor matching ratio
+
+int main(void)
+{
+    Mat img1 = imread("graf1.png", IMREAD_GRAYSCALE);
+    Mat img2 = imread("graf3.png", IMREAD_GRAYSCALE);
+
+    Mat homography;
+    FileStorage fs("H1to3p.xml", FileStorage::READ);
+    fs.getFirstTopLevelNode() >> homography;
+
+    vector<KeyPoint> kpts1, kpts2;
+    Mat desc1, desc2;
+
+    AKAZE akaze;
+    akaze(img1, noArray(), kpts1, desc1);
+    akaze(img2, noArray(), kpts2, desc2);
+
+    BFMatcher matcher(NORM_HAMMING);
+    vector< vector<DMatch> > nn_matches;
+    matcher.knnMatch(desc1, desc2, nn_matches, 2);
+
+    vector<KeyPoint> matched1, matched2, inliers1, inliers2;
+    vector<DMatch> good_matches;
+    for(size_t i = 0; i < nn_matches.size(); i++) {
+        DMatch first = nn_matches[i][0];
+        float dist1 = nn_matches[i][0].distance;
+        float dist2 = nn_matches[i][1].distance;
+
+        if(dist1 < nn_match_ratio * dist2) {
+            matched1.push_back(kpts1[first.queryIdx]);
+            matched2.push_back(kpts2[first.trainIdx]);
+        }
+    }
+
+    for(unsigned i = 0; i < matched1.size(); i++) {
+        Mat col = Mat::ones(3, 1, CV_64F);
+        col.at<double>(0) = matched1[i].pt.x;
+        col.at<double>(1) = matched1[i].pt.y;
+
+        col = homography * col;
+        col /= col.at<double>(2);
+        double dist = sqrt( pow(col.at<double>(0) - matched2[i].pt.x, 2) +
+                            pow(col.at<double>(1) - matched2[i].pt.y, 2));
+
+        if(dist < inlier_threshold) {
+            int new_i = static_cast<int>(inliers1.size());
+            inliers1.push_back(matched1[i]);
+            inliers2.push_back(matched2[i]);
+            good_matches.push_back(DMatch(new_i, new_i, 0));
+        }
+    }
+
+    Mat res;
+    drawMatches(img1, inliers1, img2, inliers2, good_matches, res);
+    imwrite("res.png", res);
+
+    double inlier_ratio = inliers1.size() * 1.0 / matched1.size();
+    cout << "A-KAZE Matching Results" << endl;
+    cout << "*******************************" << endl;
+    cout << "# Keypoints 1:                        \t" << kpts1.size() << endl;
+    cout << "# Keypoints 2:                        \t" << kpts2.size() << endl;
+    cout << "# Matches:                            \t" << matched1.size() << endl;
+    cout << "# Inliers:                            \t" << inliers1.size() << endl;
+    cout << "# Inliers Ratio:                      \t" << inlier_ratio << endl;
+    cout << endl;
+
+    return 0;
+}