Merge remote-tracking branch 'upstream/3.4' into merge-3.4

modules/dnn/include/opencv2/dnn/all_layers.hpp

@@ -77,6 +77,15 @@ CV__DNN_INLINE_NS_BEGIN
         static Ptr<Layer> create(const LayerParams &params);
     };
 
+    /**
+     * Constant layer produces the same data blob at an every forward pass.
+     */
+    class CV_EXPORTS ConstLayer : public Layer
+    {
+    public:
+        static Ptr<Layer> create(const LayerParams &params);
+    };
+
     //! LSTM recurrent layer
     class CV_EXPORTS LSTMLayer : public Layer
     {

modules/dnn/include/opencv2/dnn/dnn.hpp

@@ -88,6 +88,9 @@ CV__DNN_INLINE_NS_BEGIN
         DNN_TARGET_FPGA
     };
 
+    CV_EXPORTS std::vector< std::pair<Backend, Target> > getAvailableBackends();
+    CV_EXPORTS std::vector<Target> getAvailableTargets(Backend be);
+
     /** @brief This class provides all data needed to initialize layer.
      *
      * It includes dictionary with scalar params (which can be read by using Dict interface),

modules/dnn/include/opencv2/dnn/version.hpp

@@ -6,7 +6,7 @@
 #define OPENCV_DNN_VERSION_HPP
 
 /// Use with major OpenCV version only.
-#define OPENCV_DNN_API_VERSION 20181121
+#define OPENCV_DNN_API_VERSION 20181205
 
 #if !defined CV_DOXYGEN && !defined CV_DNN_DONT_ADD_INLINE_NS
 #define CV__DNN_INLINE_NS __CV_CAT(dnn4_v, OPENCV_DNN_API_VERSION)