image_view problem

asked 2015-11-12 09:13:47 -0500

kaygudo gravatar image

when i run : rosrun image_view stereo_view stereo:=raw_stereo image:=image_rect _approximate_sync:=true 3 screens pops up "right", "left" and "disparity" without any display.

i have attached two webcams to my usb port and expect that they should work as stereo cameras.

Plz help i am new to linux and ros.

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please repeat your attempt and in an other shell run rostopic list -v and show us the output.

Dimitri Schachmann gravatar imageDimitri Schachmann ( 2015-11-12 09:40:40 -0500 )edit

output is: Published topics: * /rosout [rosgraph_msgs/Log] 2 publishers * /rosout_agg [rosgraph_msgs/Log] 1 publisher

Subscribed topics: * /my_stereo_cam/disparity [stereo_msgs/DisparityImage] 1 subscriber * /my_stereo_cam/right/image_rect_color [sensor_msgs/Image] 1 subscriber

kaygudo gravatar imagekaygudo ( 2015-11-12 11:20:39 -0500 )edit

continued: * /rosout [rosgraph_msgs/Log] 1 subscriber * /my_stereo_cam/left/image_rect_color [sensor_msgs/Image] 1 subscriber

kaygudo gravatar imagekaygudo ( 2015-11-12 11:25:50 -0500 )edit

clearly you have no topics with your camera data published. you can not just plugin a usb camera and it will work, you need some ROS node that will read the camera data and publish this data on ROS topics. What kind of ROS node (and whether it exists) depends on the cameras.

Dimitri Schachmann gravatar imageDimitri Schachmann ( 2015-11-12 11:40:52 -0500 )edit

Can you describe your setup? What cameras are you using?

Dimitri Schachmann gravatar imageDimitri Schachmann ( 2015-11-12 11:41:09 -0500 )edit

i am using normal usb web cam "Quantum 25 mp webcam". i previously used launch file of "usb_cam-develop" package to take the video feed , but it supports only one camera at a time.I also tried with "uvc_camera" launch file "stereo_node.launch " but it didn't worked out.

kaygudo gravatar imagekaygudo ( 2015-11-12 12:09:52 -0500 )edit

it's hard to determine what your problem is. perhaps having a look at http://wiki.ros.org/libuvc_camera helps.

Dimitri Schachmann gravatar imageDimitri Schachmann ( 2015-11-13 06:33:37 -0500 )edit

also note that you first need to get the images and CameraInfo of both webcams separately into ROS. Only after using http://wiki.ros.org/camera_calibratio... you make a stereo pair out of your webcams.

Dimitri Schachmann gravatar imageDimitri Schachmann ( 2015-11-13 06:37:01 -0500 )edit