Added support of GPU in stitching seam estimators

modules/stitching/include/opencv2/stitching/detail/seam_finders.hpp

@@ -51,9 +51,6 @@ namespace detail {
 class CV_EXPORTS SeamFinder
 {
 public:
-    enum { NO, VORONOI, GC_COLOR, GC_COLOR_GRAD };
-    static Ptr<SeamFinder> createDefault(int type);
-
     virtual ~SeamFinder() {}
     virtual void find(const std::vector<Mat> &src, const std::vector<Point> &corners,
                       std::vector<Mat> &masks) = 0;
@@ -89,10 +86,16 @@ private:
 };
 
 
-class CV_EXPORTS GraphCutSeamFinder : public SeamFinder
+class CV_EXPORTS GraphCutSeamFinderBase
 {
 public:
     enum { COST_COLOR, COST_COLOR_GRAD };
+};
+
+
+class CV_EXPORTS GraphCutSeamFinder : public GraphCutSeamFinderBase, public SeamFinder
+{
+public:
     GraphCutSeamFinder(int cost_type = COST_COLOR_GRAD, float terminal_cost = 10000.f,
                        float bad_region_penalty = 1000.f);
 
@@ -105,6 +108,33 @@ private:
     Ptr<Impl> impl_;
 };
 
+
+#ifndef ANDROID
+class CV_EXPORTS GraphCutSeamFinderGpu : public GraphCutSeamFinderBase, public PairwiseSeamFinder
+{
+public:
+    GraphCutSeamFinderGpu(int cost_type = COST_COLOR_GRAD, float terminal_cost = 10000.f,
+                          float bad_region_penalty = 1000.f)
+                          : cost_type_(cost_type), terminal_cost_(terminal_cost), 
+                            bad_region_penalty_(bad_region_penalty) {}
+
+    void find(const std::vector<cv::Mat> &src, const std::vector<cv::Point> &corners, 
+              std::vector<cv::Mat> &masks);
+    void findInPair(size_t first, size_t second, Rect roi);
+
+private:
+    void setGraphWeightsColor(const cv::Mat &img1, const cv::Mat &img2, const cv::Mat &mask1, const cv::Mat &mask2,
+                              cv::Mat &terminals, cv::Mat &leftT, cv::Mat &rightT, cv::Mat &top, cv::Mat &bottom);
+    void setGraphWeightsColorGrad(const cv::Mat &img1, const cv::Mat &img2, const cv::Mat &dx1, const cv::Mat &dx2, 
+                                  const cv::Mat &dy1, const cv::Mat &dy2, const cv::Mat &mask1, const cv::Mat &mask2, 
+                                  cv::Mat &terminals, cv::Mat &leftT, cv::Mat &rightT, cv::Mat &top, cv::Mat &bottom);
+    std::vector<Mat> dx_, dy_;
+    int cost_type_;
+    float terminal_cost_;
+    float bad_region_penalty_;
+};
+#endif
+
 } // namespace detail
 } // namespace cv
 

modules/stitching/src/stitcher.cpp

@@ -63,16 +63,17 @@ Stitcher Stitcher::createDefault(bool try_use_gpu)
     {
         stitcher.setFeaturesFinder(new detail::SurfFeaturesFinderGpu());
         stitcher.setWarper(new SphericalWarperGpu());
+        stitcher.setSeamFinder(new detail::GraphCutSeamFinderGpu());
     }
     else
 #endif
     {
         stitcher.setFeaturesFinder(new detail::SurfFeaturesFinder());
         stitcher.setWarper(new SphericalWarper());
+        stitcher.setSeamFinder(new detail::GraphCutSeamFinder());
     }
 
     stitcher.setExposureCompenstor(new detail::BlocksGainCompensator());
-    stitcher.setSeamFinder(new detail::GraphCutSeamFinder());
     stitcher.setBlender(new detail::MultiBandBlender(try_use_gpu));
 
     return stitcher;

samples/cpp/stitching_detailed.cpp

@@ -132,7 +132,7 @@ std::string save_graph_to;
 string warp_type = "spherical";
 int expos_comp_type = ExposureCompensator::GAIN_BLOCKS;
 float match_conf = 0.65f;
-int seam_find_type = SeamFinder::GC_COLOR;
+string seam_find_type = "gc_color";
 int blend_type = Blender::MULTI_BAND;
 float blend_strength = 5;
 string result_name = "result.jpg";
@@ -262,14 +262,11 @@ int parseCmdArgs(int argc, char** argv)
         }
         else if (string(argv[i]) == "--seam")
         {
-            if (string(argv[i + 1]) == "no")
-                seam_find_type = SeamFinder::NO;
-            else if (string(argv[i + 1]) == "voronoi")
-                seam_find_type = SeamFinder::VORONOI;
-            else if (string(argv[i + 1]) == "gc_color")
-                seam_find_type = SeamFinder::GC_COLOR;
-            else if (string(argv[i + 1]) == "gc_colorgrad")
-                seam_find_type = SeamFinder::GC_COLOR_GRAD;
+            if (string(argv[i + 1]) == "no" ||
+                string(argv[i + 1]) == "voronoi" ||
+                string(argv[i + 1]) == "gc_color" ||
+                string(argv[i + 1]) == "gc_colorgrad")
+                seam_find_type = argv[i + 1];
             else
             {
                 cout << "Bad seam finding method\n";
@@ -550,7 +547,35 @@ int main(int argc, char* argv[])
     Ptr<ExposureCompensator> compensator = ExposureCompensator::createDefault(expos_comp_type);
     compensator->feed(corners, images_warped, masks_warped);
 
-    Ptr<SeamFinder> seam_finder = SeamFinder::createDefault(seam_find_type);
+    Ptr<SeamFinder> seam_finder;
+    if (seam_find_type == "no")
+        seam_finder = new detail::NoSeamFinder();
+    else if (seam_find_type == "voronoi")
+        seam_finder = new detail::VoronoiSeamFinder();
+    else if (seam_find_type == "gc_color")
+    {
+#ifndef ANDROID
+        if (try_gpu)
+            seam_finder = new detail::GraphCutSeamFinderGpu(GraphCutSeamFinderBase::COST_COLOR);
+        else
+#endif
+            seam_finder = new detail::GraphCutSeamFinder(GraphCutSeamFinderBase::COST_COLOR);
+    }
+    else if (seam_find_type == "gc_colorgrad")
+    {
+#ifndef ANDROID
+        if (try_gpu)
+            seam_finder = new detail::GraphCutSeamFinderGpu(GraphCutSeamFinderBase::COST_COLOR_GRAD);
+        else
+#endif
+            seam_finder = new detail::GraphCutSeamFinder(GraphCutSeamFinderBase::COST_COLOR_GRAD);
+    }
+    if (seam_finder.empty())
+    {
+        cout << "Can't create the following seam finder '" << seam_find_type << "'\n";
+        return 1;
+    }
+
     seam_finder->find(images_warped_f, corners, masks_warped);
 
     // Release unused memory