Launch file issue with Aruco_Detect.

[madgrizzle]

I'm running the melodic version with a kinect and have modified the launch per this topic:

https://github.com/UbiquityRobotics/fiducials/issues/136

Edit: See comment below

[madgrizzle]

Running melodic and having modified the launch file to work with a kinect, aruco_detect gets stuck at the 'ready' line, suggesting it never received any images on the subscribed topic.

I dug into the source code and it looks like aruco_detect.cpp is subscribe to "camera" and not "camera/compressed" as listed in the launch file? I'm still new to ROS so I might be mistaken, but I setup a topic_tools relay between /camera/rgb/image_raw and /camera, it starts working.

https://github.com/UbiquityRobotics/fiducials/blob/ff8a356217a9c23c1c392f898af0fd66eeccecbe/aruco_detect/src/aruco_detect.cpp#L582-L583

So I modified the launch file to remap "/camera" instead of "/camera/compressed" and it didn't work. BUT, if I dropped out the $(arg transport) part, it worked:

<arg name="camera" default="/camera/rgb"/>
<arg name="image" default="image_mono"/>
<arg name="transport" default="raw"/>
...
<remap from="/camera" to="$(arg camera)/$(arg image)"/>
<remap from="/camera_info" to="$(arg camera)/camera_info"/>

There's got to be a simple explanation (i.e., something I'm overlooking) but this is the only thing that worked for me running off the melodic build with a kinect camera.