Trackbar in rqt ros

Question

I am trying to interface ROS and open cv. I was able to threshold the video stream and display the output in rqt. Now I want to adjust the threshold range by creating a track bar in rqt. How could I implement it.

Answer 1

The best way in terms of integration and looks would be to create your own rqt plugin (tutorial). However you'd need to find some way to notify your node about any changes (e.g. via a service call).

Much easier and faster, and usually sufficient, is to re-use existing functionality. In this case, take a look at dynamic_reconfigure. This allows you to change parameters on the fly, you only need to define the configuration and register a callback in your code (tutorials). The GUI integrates into rqt.