4 from sensor_msgs.msg 
import Image, CameraInfo
 
    6 rospy.init_node(
"dummy_camera")
 
    8 pub = rospy.Publisher(
"~image", Image)
 
    9 pub_info = rospy.Publisher(
"~camera_info", CameraInfo)
 
   10 frame_id = rospy.get_param(
'~frame_id', 
'dummy_camera')
 
   11 width = rospy.get_param(
'~width', 640)
 
   12 height = rospy.get_param(
'~height', 480)
 
   15 while not rospy.is_shutdown():
 
   17     dummy_camera_info = CameraInfo()
 
   18     dummy_camera_info.width = width
 
   19     dummy_camera_info.height = height
 
   20     dummy_camera_info.header.frame_id = frame_id
 
   21     dummy_camera_info.header.stamp  = now
 
   22     dummy_camera_info.D = [0.0, 0.0, 0.0, 0.0, 0.0]
 
   23     dummy_camera_info.K = [525.0, 0.0, 319.5, 0.0, 525.0, 239.5, 0.0, 0.0, 1.0]
 
   24     dummy_camera_info.R = [1.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 1.0]
 
   25     dummy_camera_info.P = [525.0, 0.0, 319.5, 0.0, 0.0, 525.0, 239.5, 0.0, 0.0, 0.0, 1.0, 0.0]
 
   26     dummy_camera_info.distortion_model = 
"plumb_bob" 
   27     pub_info.publish(dummy_camera_info)
 
   30     dummy_img.width = width
 
   31     dummy_img.height = height
 
   32     dummy_img.header.frame_id = frame_id
 
   33     dummy_img.header.stamp = now
 
   34     dummy_img.step = width
 
   35     dummy_img.encoding = 
"mono8" 
   36     dummy_img.data = [0] * width * height
 
   37     pub.publish(dummy_img)