Create a node that accesses the occupancy grid and then applies thresholding on it

[gsh89]

This is the reason I want to do this:

I had encountered the issue of obstacles not being detected properly in the costmap (i.e. they were not showing up as inflated) similar to this issue. The work around suggested there basically involved using thresholding to make the map look like that created using Gmapping. Doing that helped in resolving the issue but the created map became very blocky (not like the nice looking original Cartographer maps). I was wondering if it was possible to create a copy of the original occupancy grid every time the costmap needs it , threshold it to convert it to a Gmapping style occupancy grid and publish a duplicate map topic.

Can someone please advise ?