Problem

Is there a command line process for converting raster images to another format?

Solution

There is, but if the images contain georeferencing, the raster manager batch conversion process must be used.

From the MicroStation Help, search on "command line raster" to find the topic.

The help states:
When converting file formats which refer to a dgn file for georeference information, the conversion of the raster's data will be correct, but the location of the raster will not
be kept. Since rastconv.ma operates offline, the raster formats are handled like rasters with no georeference.