Resizing Orthomosaics
Newer versions of Autodesk Civil3D may require resizing before opening large orthomosaics. If you’re having issues, you can try these steps:
- Download and install QGIS 2.18.17 (Free software)
- From your Start Menu open “QGIS Desktop 2.18.17”
- Open the .tiff files in QGIS. (You can hide the Ortho by unchecking the box in the layer menu on the left for faster processing)
- On the top bar, navigate to Raster –> Conversion –. Translate (Convert Format)
- Select input layer and output file location and name
- Check “outsize” and select the percentage to which you want to reduce the Ortho resolution.
- Click OK

- To open in Civil3D, use the command “mapiinstert” and select your resized .Tif file.