aruco_detection.pyの実装完了

Author: mizonon

crane_x7_examples_py/crane_x7_examples_py/aruco_detection.py

@@ -0,0 +1,117 @@
+# Copyright 2020 RT Corporation
+# 
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+# 
+#     http://www.apache.org/licenses/LICENSE-2.0
+# 
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+import rclpy
+from rclpy.node import Node
+
+import numpy as np
+
+# from std_msgs.msg import String
+from geometry_msgs.msg import TransformStamped
+from sensor_msgs.msg import CameraInfo, Image
+import cv2
+from cv2 import aruco
+from cv_bridge import CvBridge
+import tf2_ros
+
+from crane_x7_examples_py.utils import rotation_matrix_to_quaternion
+
+
+class ImageSubscriber(Node):
+    def __init__(self):
+        super().__init__("aruco_detection")
+        self.image_subscription = self.create_subscription(
+            Image, "/camera/color/image_raw", self.listener_callback, 10
+        )
+        self.camera_info_subscription = self.create_subscription(
+            CameraInfo, "/camera/color/camera_info", self.listener_callback, 10
+        )
+        self.tf_broadcaster = tf2_ros.TransformBroadcaster()
+
+        self.camera_info = None
+        self.bridge = CvBridge()
+
+    def image_callback(self, msg):
+        # 画像データをROSのメッセージからOpenCVの配列に変換
+        cv_img = self.bridge.imgmsg_to_cv2(msg, desired_encoding=msg.encoding)
+        cv_img = cv2.cvtColor(cv_img, cv2.COLOR_RGB2BGR)
+    
+        if self.camera_info:
+            # ArUcoマーカのデータセットを読み込む
+            # DICT_6x6_50は6x6ビットのマーカが50個収録されたもの
+            MARKER_DICT = aruco.getPredefinedDictionary(aruco.DICT_6X6_50)
+    
+            # マーカーID
+            ids = []
+    
+            # 画像座標系上のマーカ頂点位置
+            corners = []
+            
+            # マーカの検出
+            corners, ids, _ = aruco.detectMarkers(cv_img, MARKER_DICT)
+
+            # マーカの検出数
+            n_markers = len(ids)
+            
+            # カメラパラメータ
+            CAMERA_MATRIX = np.array(self.camera_info['k']).reshape(3, 3)
+            DIST_COEFFS = np.array(self.camera_info['d']).reshape(1, 5)
+            
+            # マーカ一辺の長さ 0.04 [m]
+            MARKER_LENGTH = 0.04
+            
+            # マーカが一つ以上検出された場合、マーカの位置姿勢をtfで配信
+            if n_markers > 0:
+                for i in range(n_markers):
+                    # 画像座標系上のマーカ位置を三次元のカメラ座標系に変換
+                    rvecs, tvecs, _ = cv2.aruco.estimatePoseSingleMarkers(
+                                        corners, MARKER_LENGTH, CAMERA_MATRIX, DIST_COEFFS)
+                    # tfの配信
+                    t = TransformStamped()
+                    t.header.stamp = self.get_clock().now().to_msg()
+                    t.header.frame_id = "camera_color_optical_frame"
+                    t.child_frame_id = "target_" + str(ids[i][0])
+                    t.transform.translation.x = tvecs[i][0][0]
+                    t.transform.translation.y = tvecs[i][0][1]
+                    t.transform.translation.z = tvecs[i][0][2]
+                    # 回転ベクトル→回転行列
+                    rotation_matrix, _ = cv2.Rodrigues(rvecs[i])
+                    # 回転行列からクォータニオンを求める
+                    q = rotation_matrix_to_quaternion(rotation_matrix)
+                    t.transform.rotation.x = q.x
+                    t.transform.rotation.y = q.y
+                    t.transform.rotation.z = q.z
+                    t.transform.rotation.w = q.w
+                    self.tf_broadcaster.sendTransform(t)
+                    
+    def camera_info_callback(self, msg):
+        self.camera_info = msg
+        
+        
+def main(args=None):
+    rclpy.init(args=args)
+
+    image_subscriber = ImageSubscriber()
+    rclpy.spin(image_subscriber)
+
+    # Destroy the node explicitly
+    # (optional - otherwise it will be done automatically
+    # when the garbage collector destroys the node object)
+    image_subscriber.destroy_node()
+    rclpy.shutdown()
+
+
+if __name__ == "__main__":
+    main()