fix: cv2.aruco.interpolateCornersCharuco is deprecated (backport #979) (#1090)

There has been API Changes in the newer releases of opencv2 (from
4.8.0). The PR addresses this by supporting both the old and new APIs.

Co-authored-by: Földi Tamás <tfoldi@xsi.hu>

Author: mergify[bot]

camera_calibration/src/camera_calibration/calibrator.py

@@ -88,8 +88,13 @@ def __init__(self, pattern="chessboard", n_cols = 0, n_rows = 0, dim = 0.0, mark
                 "7x7_100"    : cv2.aruco.DICT_7X7_100,
                 "7x7_250"    : cv2.aruco.DICT_7X7_250,
                 "7x7_1000"    : cv2.aruco.DICT_7X7_1000}[aruco_dict])
-            self.charuco_board = cv2.aruco.CharucoBoard_create(self.n_cols, self.n_rows, self.dim, self.marker_size,
-                    self.aruco_dict)
+            if cv2.__version__ >= '4.8.0':
+                self.charuco_board = cv2.aruco.CharucoBoard((self.n_cols, self.n_rows), self.dim, self.marker_size,
+                        self.aruco_dict)
+            else:
+                self.charuco_board = cv2.aruco.CharucoBoard_create(self.n_cols, self.n_rows, self.dim, self.marker_size,
+                        self.aruco_dict)
+            
 
 # Make all private!!!!!
 def lmin(seq1, seq2):
@@ -268,10 +273,17 @@ def _get_charuco_corners(img, board, refine):
     else:
         mono = img
 
-    marker_corners, marker_ids, _ = cv2.aruco.detectMarkers(img, board.aruco_dict)
-    if len(marker_corners) == 0:
-        return (False, None, None)
-    _, square_corners, ids = cv2.aruco.interpolateCornersCharuco(marker_corners, marker_ids, img, board.charuco_board)
+
+    if cv2.__version__ >= '4.8.0':
+        charucodetector = cv2.aruco.CharucoDetector(board.charuco_board)
+        square_corners, ids, marker_corners, marker_ids = charucodetector.detectBoard(mono)
+    else:
+        marker_corners, marker_ids, _ = cv2.aruco.detectMarkers(img, board.aruco_dict)
+
+        if len(marker_corners) == 0:
+            return (False, None, None)
+        _, square_corners, ids = cv2.aruco.interpolateCornersCharuco(marker_corners, marker_ids, img, board.charuco_board, minMarkers=1)
+
     return ((square_corners is not None) and (len(square_corners) > 5), square_corners, ids)
 
 def _get_circles(img, board, pattern):

camera_calibration/src/camera_calibration/camera_calibrator.py

@@ -317,7 +317,7 @@ def on_model_change(self, model_select_val):
         self.c.set_cammodel( CAMERA_MODEL.PINHOLE if model_select_val < 0.5 else CAMERA_MODEL.FISHEYE)
 
     def on_scale(self, scalevalue):
-        if self.c.calibrated:
+        if self.c and self.c.calibrated:
             self.c.set_alpha(scalevalue / 100.0)
 
     def button(self, dst, label, enable):