Hi, I am trying to run ar_pose node using my webcam logitech pro 9000. I am using only single webcam for pattern detection. According to the wiki page documentation it subscribes /usb_cam/image_raw (sensor_msgs/Image) and (/usb_cam/camera_info) but when i saw the documentation for "usb_cam bosch drivers" it is publishing /usb_cam/image topic. I tried to republish it using republish raw in:=usb_cam/Image out:=usb_cam/image_raw from image_transport node, which has got publish but ar_pose seems not subscribing/usb_cam/image_raw topic. Also, i get continuous stream of messages like below: [swscaler @ 0x87c9be0]No accelerated colorspace conversion found. I could not find much about it but saw some conversion related to it in file usb_cam_node.cpp line 91 and onwards usb_cam_pixel_format pixel_format; if(pixel_format_name_ == "yuyv") pixel_format = PIXEL_FORMAT_YUYV; else if(pixel_format_name_ == "uyvy") pixel_format = PIXEL_FORMAT_UYVY; else if(pixel_format_name_ == "mjpeg") { pixel_format = PIXEL_FORMAT_MJPEG; So, i have questions like, 1. How can i publish usb_cam/image_raw topic? 2. How can i rid off those warnings/ errors? Is FFMPEG creating some problem in my case? 3. It is not opening my camera in any viewer in spite of detecting it. I tried to open it using brown gscam package and image_viewer which is working fine. Any help is appreciated. Prasad -- View this message in context: http://ros-users.122217.n3.nabble.com/ar-pose-basic-questions-tp2016877p2016877.html Sent from the ROS-Users mailing list archive at Nabble.com.