I have an updated .sid layer I need to add to JOSM, but I am having difficulty finding topics or youtube videos on how to accomplish this. Any help would be greatly appreciated.
For a general description on how to add an imagery layer, see LearnOSM
Would be good to know what a “.sid layer” is, searching for it did give me too much false results and no result that was meaningful, so can you add a link describing it?
In ESRI ArcMap mapping software, a .sid (Mr.Sid) file format consists of highly compressed imagery in a proprietary form that I can bring into the map environment as a separate layer that doesn’t need a URL.
Aha, MrSID - Wikipedia.
I am pretty sure JOSM can not display this format directly.
You can use GeoServer to set up a (local) server to which JOSM can connect to display the data, but also GeoServer does not support MrSID. That page mentions that it probably by using another piece of software (mapserver) but with that you get a pretty complicated solution that is hard to set up.
One question on the MrSID data, does it have a compatible license?