请用python写一段ros程序，读取深度相机的深度图和彩色图，并分别保存至/home/hudi/pic路径下

好的，以下是一个简单的ROS程序，读取深度相机的深度图和彩色图，并将它们分别保存在/home/hudi/pic路径下：

#!/usr/bin/env python

import rospy
import cv2
from cv_bridge import CvBridge
from sensor_msgs.msg import Image, CameraInfo
import os

class DepthCameraSubscriber:
    def __init__(self):
        self.bridge = CvBridge()
        self.depth_sub = rospy.Subscriber('/camera/depth/image_raw', Image, self.depth_callback)
        self.color_sub = rospy.Subscriber('/camera/color/image_raw', Image, self.color_callback)
        self.depth_image = None
        self.color_image = None
        self.depth_info = None
        self.color_info = None

    def depth_callback(self, msg):
        self.depth_image = self.bridge.imgmsg_to_cv2(msg, desired_encoding="passthrough")

    def color_callback(self, msg):
        self.color_image = self.bridge.imgmsg_to_cv2(msg, desired_encoding="bgr8")

    def depth_info_callback(self, msg):
        self.depth_info = msg

    def color_info_callback(self, msg):
        self.color_info = msg

    def save_images(self):
        if self.depth_image is not None and self.color_image is not None:
            depth_path = os.path.join(os.environ['HOME'], 'pic', 'depth.png')
            color_path = os.path.join(os.environ['HOME'], 'pic', 'color.png')
            cv2.imwrite(depth_path, self.depth_image)
            cv2.imwrite(color_path, self.color_image)

if __name__ == '__main__':
    rospy.init_node('depth_camera_subscriber')
    depth_subscriber = DepthCameraSubscriber()

    rate = rospy.Rate(10)
    while not rospy.is_shutdown():
        depth_subscriber.save_images()
        rate.sleep()

注意：在运行此程序之前，需要先启动深度相机的ROS节点。并且需要注意文件夹/home/hudi/pic必须存在，否则程序会报错。