ros2 humble 华硕rgbd xtion驱动

记录一下：

1、sudo apt-get  install ros-humble-openni2-camera

2、ros2 launch openni2_camera camera_with_cloud.launch.py

再启动rviz2

可以看到rgb和深度图，但没有点云数据。

/camera/depth_registered/image_raw   正常

/camera/depth_registered/points           无数据

/camera/rgb/image_raw                         正常

根据rgb像素index获取对应的深度值

import rclpy
from rclpy.node import Node
from sensor_msgs.msg import Image
from cv_bridge import CvBridge
import numpy as np
import message_filters

class DepthFromRGB(Node):
    def __init__(self):
        super().__init__('depth_from_rgb')
        self.bridge = CvBridge()
        
        # 订阅RGB图像和深度图像的话题
        self.rgb_sub = message_filters.Subscriber(self, Image, '/camera/rgb/image_raw')
        self.depth_sub = message_filters.Subscriber(self, Image, '/camera/depth_registered/image_raw')
        
        # 使用消息过滤器同步RGB图像和深度图像
        self.ts = message_filters.ApproximateTimeSynchronizer([self.rgb_sub, self.depth_sub], queue_size=10, slop=0.1)
        self.ts.registerCallback(self.image_callback)
        
        # 像素索引
        self.pixel_x = 320  # 示例：图像中心的x坐标
        self.pixel_y = 240  # 示例：图像中心的y坐标

    def image_callback(self, rgb_msg, depth_msg):
        try:
            # 将ROS图像消息转换为OpenCV图像
            rgb_image = self.bridge.imgmsg_to_cv2(rgb_msg, desired_encoding='bgr8')
            depth_image = self.bridge.imgmsg_to_cv2(depth_msg, desired_encoding='passthrough')
            
            # 获取深度值
            depth_value = depth_image[self.pixel_y, self.pixel_x]
            
            # 打印深度值
            self.get_logger().info(f'Depth value at ({self.pixel_x}, {self.pixel_y}): {depth_value} meters')
        except Exception as e:
            self.get_logger().error(f'Error processing images: {e}')

def main(args=None):
    rclpy.init(args=args)
    node = DepthFromRGB()
    rclpy.spin(node)
    node.destroy_node()
    rclpy.shutdown()

if __name__ == '__main__':
    main()