catkin_was中创建一个ROS节点来订阅摄像头图像，需要按照以下步骤进行操作

好的，具体步骤如下：

1. 创建一个catkin工作空间

mkdir -p ~/catkin_ws/src
cd ~/catkin_ws/
catkin_make

2. 在src目录下创建一个ROS包

cd ~/catkin_ws/src
catkin_create_pkg my_camera_subscriber rospy cv_bridge sensor_msgs

这里创建了一个名为my_camera_subscriber的ROS包，它依赖于rospy、cv_bridge和sensor_msgs。

3. 在my_camera_subscriber包下创建一个节点

cd ~/catkin_ws/src/my_camera_subscriber/scripts
touch camera_subscriber.py
chmod +x camera_subscriber.py

4. 在camera_subscriber.py中编写代码

#!/usr/bin/env python

import rospy
from sensor_msgs.msg import Image
from cv_bridge import CvBridge
import cv2

def callback(data):
    bridge = CvBridge()
    cv_image = bridge.imgmsg_to_cv2(data, "bgr8")
    cv2.imshow("Camera", cv_image)
    cv2.waitKey(1)

def main():
    rospy.init_node("camera_subscriber", anonymous=True)
    rospy.Subscriber("/usb_cam/image_raw", Image, callback)
    rospy.spin()

if __name__ == '__main__':
    main()

这个节点会订阅ROS话题`/usb_cam/image_raw`，并且通过OpenCV显示相机图像。

5. 编译并运行节点

cd ~/catkin_ws/
catkin_make
source devel/setup.bash
rosrun my_camera_subscriber camera_subscriber.py

这样，就可以看到相机的实时图像了。