add CV_WRAP, add default Board constructor

modules/aruco/include/opencv2/aruco/board.hpp

@@ -26,6 +26,8 @@ class Dictionary;
  */
 class CV_EXPORTS_W Board {
 public:
+    CV_WRAP Board();
+
     /** @brief Provide way to create Board by passing necessary data. Specially needed in Python.
      * @param objPoints array of object points of all the marker corners in the board
      * @param dictionary the dictionary of markers employed for this board
@@ -91,7 +93,7 @@ CV_EXPORTS_W void drawPlanarBoard(const Ptr<Board> &board, Size outSize, OutputA
 
 class CV_EXPORTS_W GridBoard : public Board {
 public:
-    CV_EXPORTS_W GridBoard();
+    CV_WRAP GridBoard();
     /**
      * @brief Draw a GridBoard
      *
@@ -142,7 +144,7 @@ protected:
  */
 class CV_EXPORTS_W CharucoBoard : public Board {
 public:
-    CharucoBoard();
+    CV_WRAP CharucoBoard();
 
     // vector of chessboard 3D corners precalculated
     CV_PROP std::vector<Point3f> chessboardCorners;

modules/aruco/include/opencv2/aruco_detector.hpp

@@ -306,7 +306,7 @@ public:
      * @param _params marker detection parameters
      * @param _refineParams marker refine detection parameters
      */
-    ArucoDetector(const Ptr<Dictionary> &_dictionary = getPredefinedDictionary(DICT_4X4_50),
+    CV_WRAP ArucoDetector(const Ptr<Dictionary> &_dictionary = getPredefinedDictionary(DICT_4X4_50),
                   const Ptr<DetectorParameters> &_params = DetectorParameters::create(),
                   const Ptr<RefineParameters> &_refineParams = RefineParameters::create()):
                   dictionary(_dictionary), params(_params), refineParams(_refineParams) {}

modules/aruco/src/board.cpp

@@ -112,6 +112,8 @@ struct GridBoard::GridImpl {
 
 GridBoard::GridBoard(): gridImpl(makePtr<GridImpl>()) {}
 
+Board::Board(): dictionary(makePtr<Dictionary>(getPredefinedDictionary(PREDEFINED_DICTIONARY_NAME::DICT_4X4_50))) {}
+
 Ptr<Board> Board::create(InputArrayOfArrays objPoints, const Ptr<Dictionary> &dictionary, InputArray ids) {
     CV_Assert(objPoints.total() == ids.total());
     CV_Assert(objPoints.type() == CV_32FC3 || objPoints.type() == CV_32FC1);