路径已经改了，包括dev_ws下的bulid里的文件路径都改为我得了
这是报错
marcl@ubuntu:~$ ros2 run learning_node node_object
[INFO] [node_object]: ROS2节点示例：检测图片中的苹果
OpenCV Error: Assertion failed ((scn == 3 || scn == 4) && (depth == CV_8U || depth == CV_32F)) in cvtColor, file /build/opencv-L2vuMj/opencv-3.2.0+dfsg/modules/imgproc/src/color.cpp, line 9815
Traceback (most recent call last):
  File "/home/marcl/dev_ws/install/learning_node/lib/learning_node/node_object", line 11, in <module>
    load_entry_point('learning-node==0.0.0', 'console_scripts', 'node_object')()
  File "/home/marcl/dev_ws/install/learning_node/lib/python3.6/site-packages/learning_node/node_object.py", line 42, in main
    object_detect(image)                                                            # 苹果检测
  File "/home/marcl/dev_ws/install/learning_node/lib/python3.6/site-packages/learning_node/node_object.py", line 19, in object_detect
    hsv_img = cv2.cvtColor(image, cv2.COLOR_BGR2HSV)                               # 图像从BGR颜色模型转换为HSV模型
cv2.error: /build/opencv-L2vuMj/opencv-3.2.0+dfsg/modules/imgproc/src/color.cpp:9815: error: (-215) (scn == 3 || scn == 4) && (depth == CV_8U || depth == CV_32F) in function cvtColor