fatal:can't open depth camera

edit

when i run roslaunch freenect_launch freenect-registered-xyzrgb.launch I got following errors,and I run rosrun image_view image_view image:=/camera/ depth_registered /image_rect the window break down at once,but I can use rgb camera without any errors,Thanks everyone who is willing to help me!

 **[ INFO] [1446808989.401577431]: Starting a 3s RGB and Depth stream flush.              
[ INFO] [1446808989.401989802]: Opened 'Xbox NUI Camera' on bus 0:0 with serial number 'A22596705403327A'       
 [ WARN] [1446808989.616986731]: Could not find any compatible depth output mode for 1. Falling back to default depth         output mode 1.        
[ INFO] [1446808989.635605723]: rgb_frame_id = 'camera_rgb_optical_frame'       
[ INFO] [1446808989.635924353]: depth_frame_id = 'camera_depth_optical_frame'          
 [ WARN] [1446808989.651085845]: Camera calibration file /home/unicorn/.ros/camera_info/rgb_A22596705403327A.yaml not found.            
 [ WARN] [1446808989.651150401]: Using default parameters for RGB camera calibration. 
[ WARN] [1446808989.651205748]: Camera calibration file /home/unicorn/.ros/camera_info       /depth_A22596705403327A.yaml not found.            
 [ WARN] [1446808989.651243210]: Using default parameters for IR camera calibration. 
 [ INFO] [1446808992.402965026]: Stopping device RGB and Depth stream flush.**