Visualization/Overlay of scan onto depthimage

[YBachmann]

We currently use a robot with multiple tilted cameras, which necessitates carefull parameterization of scan_height (and scan_offset, see PR #80) such that e.g. the floor/ceiling in the depthimage is not used for calculation of the laserscan.

It would be really useful if there was a way to see an overlay on the depthimage of the rows beeing used for the laserscan.
I saw that in the wiki page under section 1.2 there is an overlay of the laserscan onto the depthimage. Was this manually created or is there already a way to visualize this overlay for a live depthimage?

I would be open to implementing an overlay of the scan_height (and scan_offset) for easier parameterization and debugging, either directly inside this package or as a separate tool. But before I do that I wanted to ask if something like this already exists and if other people might find this useful, too.

[YBachmann]

I wrote a simple python node as a proof of concept, which takes in the same parameter.yaml file as the depthimage_to_laserscan-node and publishes a visualization of the scan_height and scan_offset on the RGB- and Depthimage:

In this image a scan_offset of 0.45 and a scan_height of 180px was used (image height = 720).
Using the visualizations it is really easy to set the parameters such that the right parts of the image (e.g. not the floor/ceiling) are used for the laserscan-generation.