roslaunch error

edit

*Hi , I am trying to run roslaunch ros2opencv uvc_cam.launch , it gives me the following error :

... logging to /home/nyan/.ros/log/1d192da2-d1ca-11e3-8a0d-b870f417ccf2/roslaunch-nyan-Ideapad-Z460-8001.log
Checking log directory for disk usage. This may take awhile.
Press Ctrl-C to interrupt
Done checking log file disk usage. Usage is <1GB.

started roslaunch server nyan-Ideapad-Z460:45076

Summary

PARAMETERS
 * /rosdistro
 * /rosversion
 * /uvc_cam_node/device
 * /uvc_cam_node/exposure
 * /uvc_cam_node/frame_rate
 * /uvc_cam_node/height
 * /uvc_cam_node/width

NODES
  /
    uvc_cam_node (uvc_cam/uvc_cam_node)

ROS_MASTER_URI=localhost:11311

core service [/rosout] found
ERROR: cannot launch node of type [uvc_cam/uvc_cam_node]: uvc_cam
ROS path [0]=/opt/ros/hydro/share/ros
ROS path [1]=/opt/ros/hydro/share
ROS path [2]=/opt/ros/hydro/stacks
No processes to monitor
shutting down processing monitor...
... shutting down processing monitor complete

Can anyone help me troubleshoot this error? I am a beginner in ros , and thus I will appreciate simple explanations. Thanks in advance.*