Clover

Viewing images from cameras

To view images from cameras (or other ROS topics), you can use rviz, rqt, or watch them in a browser using web_video_server.

See read more about using rqt.

Viewing in a browser

To view a video-stream, you have to connect to Wi-Fi network of the Clover (clover-xxxx), navigate to page http://192.168.11.1:8080/open in new window, and choose the topic.

Viewing web_video_server

If the image is transmitted too slow, you can speed it up by changing GET parameter quality (from 1 to 100), which is responsible for video-stream compression, for example:

http://192.168.11.1:8080/stream_viewer?topic=/main_camera/image_raw&quality=1open in new window

At the URL above, a stream from the main camera will be available in the minimum possible quality.

Parameters width, height, etc. re also available. Read more about web_video_server: http://wiki.ros.org/web_video_serveropen in new window.

Browse with rqt_image_view

To browse images with the rqt tools the user needs a computer with Ubuntu 18.04 and ROS Melodicopen in new window.

Connect to the Clover Wi-Fi network an run rqt_image_view with its IP-address:

ROS_MASTER_URI=http://192.168.11.1:11311 rqt_image_view

Choose a topic for browsing, for example /main_camera/image_raw:

rqt_image_view

To reduce network load and reduce latency, use a compressed version of the topic – /main_camera/image_raw/compressed.

To change the compression settings use the rqt-plugin Dynamic Reconfigure:

rqt_image_view+rqt_dynamic_reconfigure

Refer to more about rviz and rqt.