Source: Innovyze Support Portal
When working with a model, from time to time we’ll need to load background images into the model.
Unlike GIS software, some modeling packages cannot handle large files. In this article we’ll show how to use ArcMap to reduce the size of an image file.
1. the bigger the cell size, the smaller the file size
2. changing the file type might change the compression ratio to reduce the size
3. use a higher compression ratio
4. you can zoom to a smaller area and only export the current extent
NOTE: XPSWMM only supports certain image type. You might need to test a few different options.
For QGIS,