sensor_mgs

sensor_msgs §

Image §

• 注意图像信息和OpenCV使用的Numpy不直接兼容，必须经过imgmsg_to_cv2或cv2_to_imgmsg的转换
• 获取时：

  def get_rgb(self):
      try:
          msg = rospy.wait_for_message("/front_cam/color/raw", Image, timeout=1)
          self.color_raw = self.bridge.imgmsg_to_cv2(msg, "bgr8")
      except rospy.ROSException:
          print("Timeout! No image received.")
          exit()

  或

  def callback(self, msg):
      try:
          self.color_raw = self.bridge.imgmsg_to_cv2(msg, desired_encoding="bgr8")
      except Exception as e:
          rospy.logerr(f"CV_BRIDGE EXCEPTION: {e}")
          return

• 发布时

  def pub_img(self):
      if self.color_raw is not None:
          img_msg = self.bridge.cv2_to_imgmsg(self.color_raw)
          self.img_pub.publish(img_msg)

PointCloud §

• 已过时，用PointCloud2代替

PointCloud2 §

• 可以设定长宽（Organized，如height=240,width=320），或不设定长宽（默认height=1宽度为点云总数，如width=240*320）
• 需要将header.frame_id设置为特定TF（如world）
• 调用point_cloud2(header, fields, points)创建点云信息 header包含参考坐标系，fields为描述符，points为具体数据
• 代码示例Python参考，C++参考

import struct
from sensor_msgs import point_cloud2
from sensor_msgs.msg import PointCloud2, PointField
from std_msgs.msg import Header