From 9b4cf896fd4a92817b0ffef75014a5a6372443af Mon Sep 17 00:00:00 2001
From: Quentin <quentin.chateau@gmail.com>
Date: Thu, 6 Oct 2016 15:40:05 +0200
Subject: [PATCH] Added AKAZE features in the stitcher pipeline (issue #6474)

---
 .../opencv2/stitching/detail/matchers.hpp     | 21 +++++++++++++++++++
 modules/stitching/src/matchers.cpp            | 21 +++++++++++++++++++
 2 files changed, 42 insertions(+)

diff --git a/modules/stitching/include/opencv2/stitching/detail/matchers.hpp b/modules/stitching/include/opencv2/stitching/detail/matchers.hpp
index eccc41172a..a46efc5760 100644
--- a/modules/stitching/include/opencv2/stitching/detail/matchers.hpp
+++ b/modules/stitching/include/opencv2/stitching/detail/matchers.hpp
@@ -131,6 +131,27 @@ private:
     Size grid_size;
 };
 
+/** @brief AKAZE features finder. :
+
+@sa detail::FeaturesFinder, AKAZE
+*/
+class CV_EXPORTS AKAZEFeaturesFinder : public detail::FeaturesFinder
+{
+public:
+    AKAZEFeaturesFinder(int descriptor_type = AKAZE::DESCRIPTOR_MLDB,
+                        int descriptor_size = 0,
+                        int descriptor_channels = 3,
+                        float threshold = 0.001f,
+                        int nOctaves = 4,
+                        int nOctaveLayers = 4,
+                        int diffusivity = KAZE::DIFF_PM_G2);
+
+private:
+    void find(InputArray image, detail::ImageFeatures &features);
+
+    Ptr<AKAZE> akaze;
+};
+
 
 #ifdef HAVE_OPENCV_XFEATURES2D
 class CV_EXPORTS SurfFeaturesFinderGpu : public FeaturesFinder
diff --git a/modules/stitching/src/matchers.cpp b/modules/stitching/src/matchers.cpp
index 3cf79822f0..df424a797a 100644
--- a/modules/stitching/src/matchers.cpp
+++ b/modules/stitching/src/matchers.cpp
@@ -462,6 +462,27 @@ void OrbFeaturesFinder::find(InputArray image, ImageFeatures &features)
     }
 }
 
+AKAZEFeaturesFinder::AKAZEFeaturesFinder(int descriptor_type,
+                                         int descriptor_size,
+                                         int descriptor_channels,
+                                         float threshold,
+                                         int nOctaves,
+                                         int nOctaveLayers,
+                                         int diffusivity)
+{
+    akaze = AKAZE::create(descriptor_type, descriptor_size, descriptor_channels,
+                          threshold, nOctaves, nOctaveLayers, diffusivity);
+}
+
+void AKAZEFeaturesFinder::find(InputArray image, detail::ImageFeatures &features)
+{
+    CV_Assert((image.type() == CV_8UC3) || (image.type() == CV_8UC1));
+    Mat descriptors;
+    UMat uimage = image.getUMat();
+    akaze->detectAndCompute(uimage, UMat(), features.keypoints, descriptors);
+    features.descriptors = descriptors.getUMat(ACCESS_READ);
+}
+
 #ifdef HAVE_OPENCV_XFEATURES2D
 SurfFeaturesFinderGpu::SurfFeaturesFinderGpu(double hess_thresh, int num_octaves, int num_layers,
                                              int num_octaves_descr, int num_layers_descr)