I'm having an issue with geo-referenced mosaic imagery being extremely large after importing into Civil3D from ArcMap. Hoping some people here can chime in on a possible way to fix this issue.
The current workflow I'm going through is downloading imagery from USGS Earth Explorer, georeferencing said imagery into a new projection in ArcMap, and then importing that imagery into Civil3D so our CAD drafters can begin work on a new .dwg basefile. For the scope of some of our projects, the imagery can sometimes be a mosaic of four separate images.
This is causing major problems for my co-workers who work in Civil3D, as the base imagery for them to begin their drafting can bring the .dwg file to an unreasonable size. While the .dwg itself seems to be reasonable in file size (3,000 or 4,000k), the mosaiced, georeferenced imagery being put into the file is (in the case of four tiles) 392MB in size. This is seriously causing a choke in our workflow, particularly as we export Civil3D drawings into PDF.
The drafters have created "viewports" only showing a small section of the imagery (our final output can be several PDF export sheets showing different areas of our engineering designs), but each PDF still exports at around 9MB in size - way too big for the purposes of our organization and client specifications. Even "clipping" the imagery to our area of focus doesn't seem to help, as the file sizes for the exported PDF documents remain the same.
Can anyone offer any tips or techniques that might allow us to substantially reduce the file size of the imagery, yet not compromise resolution? Thanks!