How can I subscribe to /usb_cam/image_raw topic?
cest@ubuntu:~/chaitra/vmav-ros-pkg/calibration/camera_calibration/devel/lib/camera_calibration$ ./mono_camera_calibration /usb_cam/camera_info
[ INFO] [1469511941.900363248]: Camera model: Mei
[ INFO] [1469511941.916396659]: Waiting for camera information...
How can I subscribe to /usb_cam/image_raw topic? cest@ubuntu:~/chaitra/vmav-ros-pkg/calibration/camera_calibration/devel/lib/camera_calibration$ ./mono_camera_calibration /usb_cam/camera_info [ INFO] [1469511941.900363248]: Camera model: Mei [ INFO] [1469511941.916396659]: Waiting for camera information...
Program waits and stuck here.