Nice, that you consider to help with the development. That’s great.
I checked the code for the image export. It seems that only a few lines need to be changed.
I have made this already on a branch. Would be great if you could test it. I have not. Just coded.
The branch is named mp_write_images_as_BigGeotiffs
Here you can see the changes:
Are you already familiar with building SNAP software?
If not take a look at our wiki:
Cookbook- SNAP Wiki (atlassian.net)
Other options like pconvert do not consider vectordata and layers.
But this could be implemented. pconvert would be a good place for this.
Actually we have this already listed in this issue
[SNAP-624] Turn various SNAP Desktop actions into reusable API - JIRA (atlassian.net)
as ‘multi-layer views incl. legends and export as images’.
But not only the RGB channels need to be configured but also all the layers which shall be used. To do this, some kind of configuration file is needed.
As alternative you can implement also you own little program for your specific needs.
See this:
Exporting RGB image with vector layers - development / python - STEP Forum (esa.int)
Or if you prefer Python:
snap-engine/snappy_write_image.py at 81577c9811882440a5f1b026aaacbefa5b857cfe · senbox-org/snap-engine (github.com)